@classmethod<EOL><INDENT>def from_params(cls, params):<DEDENT>
result = cls()<EOL>result.params = params<EOL>return result<EOL>
In the case where the params is a mutable sequence (list or dictionary)
and it may change before this class is called, one may explicitly use a
reference to the params rather than using *args or **kwargs which will
copy the values and not reference them.