Execute (List of available fixers is empty):
  call ale#fix#registry#Clear()

Then (List of applicable fixers for python file is empty):
  AssertEqual [], ale#fix#registry#GetApplicableFixers('python')

Execute (Add ruby fixer):
  call ale#fix#registry#Add('ruby_fixer', 'fixer_fun', ['ruby'], 'ruby fixer')

Then (List of applicable fixers for python file is still empty):
  AssertEqual [], ale#fix#registry#GetApplicableFixers('python')

Execute (Add generic fixer):
  call ale#fix#registry#Add('generic_fixer', 'fixer_fun', [], 'generic fixer')

Then (Generic fixer should be returned as applicable for python file):
  AssertEqual ['generic_fixer'], ale#fix#registry#GetApplicableFixers('python')

Execute (Add python fixer):
  call ale#fix#registry#Add('python_fixer', 'fixer_func', ['python'], 'python fixer')

Then (List of fixers should contain both generic and python fixers):
  AssertEqual ['generic_fixer', 'python_fixer'], ale#fix#registry#GetApplicableFixers('python')