code: def read_bytes(self, n):
      data = self.buffer.read(n)
      self.logger.debug("received data:")
      self.logger.debug(data.hex())
      if not data:
          raise PostgresEmptyDataException(
              "Expected data inside of buffer when performing read_bytes"
          )
      else:
          return data
  
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 3 for calling the PostgresPacketReader obj's underlying member method code with example usage: obj.read_bytes(n) and returns: data