parameters: (self, key)
return_statement: return self.code_units[key]
docstring: Overload the [] operator to give out code units
docstring_summary: Overload the [] operator to give out code units
docstring_tokens: Overload the [] operator to give out code units
function: def __getitem__(self, key):
          """Overload the [] operator to give out code units"""
          return self.code_units[key]
function_tokens: def __getitem__ ( self , key ) : return self . code_units [ key ]