diff --git a/src/Utilities/objective_container.jl b/src/Utilities/objective_container.jl
index 62272536f9..5effee8f26 100644
--- a/src/Utilities/objective_container.jl
+++ b/src/Utilities/objective_container.jl
@@ -116,58 +116,29 @@ function MOI.supports(
     return true
 end
 
-function _get_single_variable(o::ObjectiveContainer{T}) where {T}
-    return o.single_variable::MOI.VariableIndex
-end
-
-function _get_scalar_affine(o::ObjectiveContainer{T}) where {T}
-    return o.scalar_affine::MOI.ScalarAffineFunction{T}
-end
-
-function _get_scalar_quadratic(o::ObjectiveContainer{T}) where {T}
-    return o.scalar_quadratic::MOI.ScalarQuadraticFunction{T}
-end
-
-function _get_scalar_nonlinear(o::ObjectiveContainer{T}) where {T}
-    return o.scalar_nonlinear::MOI.ScalarNonlinearFunction
-end
-
-function _get_vector_variables(o::ObjectiveContainer{T}) where {T}
-    return o.vector_variables::MOI.VectorOfVariables
-end
-
-function _get_vector_affine(o::ObjectiveContainer{T}) where {T}
-    return o.vector_affine::MOI.VectorAffineFunction{T}
-end
-
-function _get_vector_quadratic(o::ObjectiveContainer{T}) where {T}
-    return o.vector_quadratic::MOI.VectorQuadraticFunction{T}
-end
-
-function _get_vector_nonlinear(o::ObjectiveContainer{T}) where {T}
-    return o.vector_nonlinear::MOI.VectorNonlinearFunction
-end
+_not_nothing(x) = x
+_not_nothing(::Nothing) = error("Unexpected internal error.")
 
 function MOI.get(
     o::ObjectiveContainer{T},
     ::MOI.ObjectiveFunction{F},
 ) where {T,F}
     if o.scalar_affine !== nothing
-        return convert(F, _get_scalar_affine(o))
+        return convert(F, _not_nothing(o.scalar_affine))
     elseif o.single_variable !== nothing
-        return convert(F, _get_single_variable(o))
+        return convert(F, _not_nothing(o.single_variable))
     elseif o.scalar_quadratic !== nothing
-        return convert(F, _get_scalar_quadratic(o))
+        return convert(F, _not_nothing(o.scalar_quadratic))
     elseif o.scalar_nonlinear !== nothing
-        return convert(F, _get_scalar_nonlinear(o))
+        return convert(F, _not_nothing(o.scalar_nonlinear))
     elseif o.vector_variables !== nothing
-        return convert(F, _get_vector_variables(o))
+        return convert(F, _not_nothing(o.vector_variables))
     elseif o.vector_affine !== nothing
-        return convert(F, _get_vector_affine(o))
+        return convert(F, _not_nothing(o.vector_affine))
     elseif o.vector_quadratic !== nothing
-        return convert(F, _get_vector_quadratic(o))
+        return convert(F, _not_nothing(o.vector_quadratic))
     elseif o.vector_nonlinear !== nothing
-        return convert(F, _get_vector_nonlinear(o))
+        return convert(F, _not_nothing(o.vector_nonlinear))
     end
     # The default if no objective is set.
     return convert(F, zero(MOI.ScalarAffineFunction{T}))
@@ -294,11 +265,14 @@ function MOI.modify(
     change::MOI.AbstractFunctionModification,
 ) where {T}
     if o.single_variable !== nothing
-        o.single_variable = modify_function!(_get_single_variable(o), change)
+        o.single_variable =
+            modify_function!(_not_nothing(o.single_variable), change)
     elseif o.scalar_affine !== nothing
-        o.scalar_affine = modify_function!(_get_scalar_affine(o), change)
+        o.scalar_affine =
+            modify_function!(_not_nothing(o.scalar_affine), change)
     elseif o.scalar_quadratic !== nothing
-        o.scalar_quadratic = modify_function!(_get_scalar_quadratic(o), change)
+        o.scalar_quadratic =
+            modify_function!(_not_nothing(o.scalar_quadratic), change)
     elseif o.scalar_nonlinear !== nothing
         throw(
             MOI.ModifyObjectiveNotAllowed(
@@ -308,11 +282,14 @@ function MOI.modify(
             ),
         )
     elseif o.vector_variables !== nothing
-        o.vector_variables = modify_function!(_get_vector_variables(o), change)
+        o.vector_variables =
+            modify_function!(_not_nothing(o.vector_variables), change)
     elseif o.vector_quadratic !== nothing
-        o.vector_quadratic = modify_function!(_get_vector_quadratic(o), change)
+        o.vector_quadratic =
+            modify_function!(_not_nothing(o.vector_quadratic), change)
     elseif o.vector_affine !== nothing
-        o.vector_affine = modify_function!(_get_vector_affine(o), change)
+        o.vector_affine =
+            modify_function!(_not_nothing(o.vector_affine), change)
     elseif o.vector_nonlinear !== nothing
         throw(
             MOI.ModifyObjectiveNotAllowed(
@@ -336,13 +313,14 @@ end
 
 function MOI.delete(o::ObjectiveContainer, x::MOI.VariableIndex)
     if o.single_variable !== nothing
-        if x == _get_single_variable(o)
+        if x == _not_nothing(o.single_variable)
             _empty_keeping_sense(o)
         end
     elseif o.scalar_affine !== nothing
-        o.scalar_affine = remove_variable(_get_scalar_affine(o), x)
+        o.scalar_affine = remove_variable(_not_nothing(o.scalar_affine), x)
     elseif o.scalar_quadratic !== nothing
-        o.scalar_quadratic = remove_variable(_get_scalar_quadratic(o), x)
+        o.scalar_quadratic =
+            remove_variable(_not_nothing(o.scalar_quadratic), x)
     elseif o.scalar_nonlinear !== nothing
         throw(
             MOI.DeleteNotAllowed(
@@ -352,14 +330,16 @@ function MOI.delete(o::ObjectiveContainer, x::MOI.VariableIndex)
             ),
         )
     elseif o.vector_variables !== nothing
-        o.vector_variables = remove_variable(_get_vector_variables(o), x)
+        o.vector_variables =
+            remove_variable(_not_nothing(o.vector_variables), x)
         if isempty(o.vector_variables.variables)
             _empty_keeping_sense(o)
         end
     elseif o.vector_affine !== nothing
-        o.vector_affine = remove_variable(_get_vector_affine(o), x)
+        o.vector_affine = remove_variable(_not_nothing(o.vector_affine), x)
     elseif o.vector_quadratic !== nothing
-        o.vector_quadratic = remove_variable(_get_vector_quadratic(o), x)
+        o.vector_quadratic =
+            remove_variable(_not_nothing(o.vector_quadratic), x)
     elseif o.vector_nonlinear !== nothing
         throw(
             MOI.DeleteNotAllowed(
@@ -375,13 +355,14 @@ end
 function MOI.delete(o::ObjectiveContainer, x::Vector{MOI.VariableIndex})
     keep = v -> !(v in x)
     if o.single_variable !== nothing
-        if _get_single_variable(o) in x
+        if _not_nothing(o.single_variable) in x
             _empty_keeping_sense(o)
         end
     elseif o.scalar_affine !== nothing
-        o.scalar_affine = filter_variables(keep, _get_scalar_affine(o))
+        o.scalar_affine = filter_variables(keep, _not_nothing(o.scalar_affine))
     elseif o.scalar_quadratic !== nothing
-        o.scalar_quadratic = filter_variables(keep, _get_scalar_quadratic(o))
+        o.scalar_quadratic =
+            filter_variables(keep, _not_nothing(o.scalar_quadratic))
     elseif o.scalar_nonlinear !== nothing
         throw(
             MOI.DeleteNotAllowed(
@@ -391,14 +372,16 @@ function MOI.delete(o::ObjectiveContainer, x::Vector{MOI.VariableIndex})
             ),
         )
     elseif o.vector_variables !== nothing
-        o.vector_variables = filter_variables(keep, _get_vector_variables(o))
+        o.vector_variables =
+            filter_variables(keep, _not_nothing(o.vector_variables))
         if isempty(o.vector_variables.variables)
             _empty_keeping_sense(o)
         end
     elseif o.vector_affine !== nothing
-        o.vector_affine = filter_variables(keep, _get_vector_affine(o))
+        o.vector_affine = filter_variables(keep, _not_nothing(o.vector_affine))
     elseif o.vector_quadratic !== nothing
-        o.vector_quadratic = filter_variables(keep, _get_vector_quadratic(o))
+        o.vector_quadratic =
+            filter_variables(keep, _not_nothing(o.vector_quadratic))
     elseif o.vector_nonlinear !== nothing
         throw(
             MOI.DeleteNotAllowed(