<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def encode_dict(values_dict):
 """Encode a dictionary into protobuf ``Value``-s. Args: values_dict (dict):
 The dictionary to encode as protobuf fields. Returns: Dict[str, ~google.cloud.firestore_v1beta1.types.Value]: A dictionary of string keys and ``Value`` protobufs as dictionary values. """

    return {key: encode_value(value) for key, value in six.iteritems(values_dict)}