code: def compiled_named_imports(self):
          
          res = []
          if self.postgres_types:
              res.append(
                  ALCHEMY_TEMPLATES.named_import.safe_substitute(
                      module='sqlalchemy.dialects.postgresql',
                      labels=", ".join(self.postgres_types)))
          if self.mutable_dict_types:
              res.append(
                  ALCHEMY_TEMPLATES.named_import.safe_substitute(
                      module='sqlalchemy.ext.mutable', labels='MutableDict'
                  ))
          return "\n".join(res)
docs: Returns compiled named imports required for the model