code: def write_var_long(self, datum):
      while datum & 0x80 != 0:
          self.write((datum & 0x80).to_bytes(1, "big"))
          datum <<= 7
      self.write(datum.to_bytes(1, "big"))
  
imports: import struct
  from avro.io import AvroTypeException, BinaryDecoder, BinaryEncoder, DatumReader, DatumWriter, SchemaResolutionException, Validate
label_desc: Use image node_id 4 for calling the FlinkAvroEncoder obj's underlying member method code with example usage: obj.write_var_long(datum) without return types