code: def write_char(self, c, write_file: BinaryIO):
      pack = "!c"
      packed_binary = struct.pack(pack, c)
      write_file.write(packed_binary)
  
imports: import struct
  from typing import List, Any, BinaryIO, Sequence, Dict
  from mindsdb.api.postgres.postgres_proxy.utilities import strip_null_byte
  from mindsdb.utilities import log
  import time
  from mindsdb.api.postgres.postgres_proxy.postgres_packets.postgres_fields import PostgresField
  from mindsdb.api.postgres.postgres_proxy.postgres_packets.postgres_message_identifiers import PostgresBackendMessageIdentifier, PostgresFrontendMessageIdentifier, PostgresAuthType
label_desc: Use image node_id 5 for calling the PostgresPacketBuilder obj's underlying member method code with example usage: obj.write_char(c, write_file) without return types