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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def process_fields_param(fields):
 """ Process 'fields' ES param. * Fields list is split if needed * '_type' field is added, if not present, so the actual value is displayed instead of 'None' """

    if not fields:
        return fields
    if isinstance(fields, six.string_types):
        fields = split_strip(fields)
    if '_type' not in fields:
        fields.append('_type')
    return {
        '_source_include': fields,
        '_source': True,
    }