Add staticmethod decorator to sale default

This was overlooked during migration. A test has been
added to ensure the behavior

The xml test file ahs been removed as its unused
Call the parameter passed in classmethod as cls rather than self
Merge pull request #13 from shalabhaggarwal/develop

Call the parameter passed in classmethod as cls rather than self
Resolved flake8 issues #2351

Review ID: 391001
Merge pull request #15 from priyankarani/feature/task-2351

Resolved flake8 issues #2351
Bump version to 2.6.0.2

#2351
Merge branch 'release/2.6.0.2'