<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _get_diff(environ, label, pop=False):
 """Get previously frozen key-value pairs. :param str label: The name for the frozen environment. :param bool pop: Destroy the freeze after use; only allow application once. :returns: ``dict`` of frozen values. """

    if pop:
        blob = environ.pop(_variable_name(label), None)
    else:
        blob = environ.get(_variable_name(label))

    return _loads(blob) if blob else {}