CodeShovel unable to generate JSON file for abstract method

[ishtiaque05]

Test file: https://github.com/checkstyle/checkstyle/blob/master/src/test/resources/com/puppycrawl/tools/checkstyle/checks/coding/illegaltype/InputIllegalTypeAbstractClassNames.java#L6

I tried generating method history of abstract method getClassInfo in the test file location with the following command
java -jar codeshovel-0.3.1-SNAPSHOT.jar -repopath checkstyle -filepath src/test/resources/com/puppycrawl/tools/checkstyle/checks/coding/illegaltype/InputIllegalTypeAbstractClassNames.java -methodname getClassInfo -startline 6

This is the output with no JSON file generated:

#########################################################################
STARTING ANALYSIS FOR FILE src/test/resources/com/puppycrawl/tools/checkstyle/checks/coding/illegaltype/InputIllegalTypeAbstractClassNames.java
FINISHED ANALYSIS FOR FILE src/test/resources/com/puppycrawl/tools/checkstyle/checks/coding/illegaltype/InputIllegalTypeAbstractClassNames.java
#########################################################################