docs: def from_mapping(cls, mapping):
          """
          Produces a set of parameters from a mapping
          """
          group = cls()
          for name, value in mapping.items():
              if name.startswith('_'):
                  continue
              group[name] = Parameter(
                  name=name,
                  value=value,
                  constraint=Parameter.constraint_from_type(value),
              )
          return group