<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _drop_none_values(dictionary: Dict) -> Dict: """Drops fields from a dictionary where value is None. {'greeting': 'hello'} """

    return {key: value for key, value in dictionary.items() if value is not None}