code: def write_map(self, writer_schema, datum, encoder):
      if len(datum) > 0:
          encoder.write_var_long(len(datum))
          for key, val in datum.items():
              encoder.write_utf8(key)
              self.write_data(writer_schema.values, val, encoder)
      encoder.write_var_long(0)
  
imports: import struct
  from avro.io import AvroTypeException, BinaryDecoder, BinaryEncoder, DatumReader, DatumWriter, SchemaResolutionException, Validate
label_desc: Use image node_id 3 for calling the FlinkAvroDatumWriter obj's underlying member method code with example usage: obj.write_map(writer_schema, datum, encoder) without return types