fix leaky error where init_hidden=True and membrane is explicit

snntorch/_neurons/leaky.py

@@ -160,13 +160,15 @@ def __init__(
         )
 
         self._init_mem()
+        self.init_hidden = init_hidden
 
         if self.reset_mechanism_val == 0:  # reset by subtraction
             self.state_function = self._base_sub
         elif self.reset_mechanism_val == 1:  # reset to zero
             self.state_function = self._base_zero
         elif self.reset_mechanism_val == 2:  # no reset, pure integration
             self.state_function = self._base_int
+
 
     def _init_mem(self):
         mem = torch.zeros(1)
@@ -183,6 +185,11 @@ def init_leaky(self):
     def forward(self, input_, mem=None):
         if not mem == None:
             self.mem = mem
+
+        if self.init_hidden and not mem == None:
+            raise TypeError(
+                "mem should not be passed as an argument while `init_hidden=True`"
+            )
 
         if not self.mem.shape == input_.shape:
             self.mem = torch.zeros_like(input_, device=self.mem.device)