Consistent Docstring

[pankajastro]

I see the following item is not consistent for docstring

• private method docstring, for some private methods we do document the param but for some, we do not
• For method public/private, for some methods, we do have the return statement in the docstring for most of the places we do not have
• class/methods param type (rtype), at someplace we have rtype for param but most of the place we do not have
• if the class do not have __init__ then at someplace do document param of class