<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def iter_field_objects(fields):
 """ Iterate over fields. Supports list of (k, v) tuples and dicts, and lists of :class:`~urllib3.fields.RequestField`. """

    if isinstance(fields, dict):
        i = six.iteritems(fields)
    else:
        i = iter(fields)

    for field in i:
        if isinstance(field, RequestField):
            yield field
        else:
            yield RequestField.from_tuples(*field)