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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 get_field(self, field_type):
 """Return the value for the 'field_type' field in oxm_match_fields. Args: field_type (~pyof.v0x04.common.flow_match.OxmOfbMatchField, ~pyof.v0x04.common.flow_match.OxmMatchFields):
 The type of the OXM field you want the value. Returns: The integer number of the 'field_type' if it exists. Otherwise return None. """

        for field in self.oxm_match_fields:
            if field.oxm_field == field_type:
                return field.oxm_value

        return None