code: def from_bytes(cls, key: bytes) -> RSAPublicKey:
      key = serialization.load_ssh_public_key(key)
      if not isinstance(key, rsa.RSAPublicKey):
          raise ValueError(f"Expected an RSA public key, got {key}")
      return cls(key)
  
imports: from __future__ import annotations
  import base64
  import threading
  from abc import ABC, abstractmethod
  from cryptography import exceptions
  from cryptography.hazmat.primitives import hashes, serialization
  from cryptography.hazmat.primitives.asymmetric import padding, rsa
label_desc: Use image node_id 4 for calling the RSAPublicKey obj's underlying member method code with example usage: obj.from_bytes(cls, key) and returns: cls