Deleted unused cflow_call and gprof_call files.
Dependency injection of line parser instances eliminated to simplify Call construction interface. Instances of the required line parsers are obtained in their corresponding constructor methods (from_cflow and from_gprof) in Call class. Fixed some circular reference issue. This code smells a little bit.
Removed import statements from modules __init__.py files and updated the rest of the code base accordingly.
Renamed call test case file.
Re-initializing object when load method is called before loading new string in line parser classes.
All tests green1
Added file names to test gprof output data.