'Return the identity of the Term that would be constructed from the
given arguments.
Identities that compare equal will cause us to return a cached instance
rather than constructing a new one.  We do this primarily because it
makes dependency resolution easier.
This is a classmethod so that it can be called from Term.__new__ to
determine whether to produce a new instance.'

@classmethod
def _static_identity(cls, domain, dtype, missing_value, window_safe, ndim, params):

    return (cls, domain, dtype, missing_value, window_safe, ndim, params)
