parameters: (self, sig)
return_statement: return self._impl_keys[sig.args]
docstring: Get the implementation key (used by the target context) for the
          given signature.
docstring_summary: Get the implementation key (used by the target context) for the
          given signature.
docstring_tokens: Get the implementation key ( used by the target context ) for the given signature .
function: def get_impl_key(self, sig):
          """
          Get the implementation key (used by the target context) for the
          given signature.
          """
          return self._impl_keys[sig.args]
function_tokens: def get_impl_key ( self , sig ) : return self . _impl_keys [ sig . args ]