code: def swapkey(self, old_key, new_key, new_value=None):
          
          if self.has_resolvers:
              maps = self.resolvers.maps + self.scope.maps
          else:
              maps = self.scope.maps
  
          maps.append(self.temps)
  
          for mapping in maps:
              if old_key in mapping:
                  mapping[new_key] = new_value
                  return
docs: Replace a variable name, with a potentially new value.
  
          Parameters
          ----------
          old_key : str
              Current variable name to replace
          new_key : str
              New variable name to replace `old_key` with
          new_value : object
              Value to be replaced along with the possible renaming