code: def find(self, substring):
          '''
          byte-like -> int
          Finds the index of substring
          '''
          if isinstance(substring, ByteData):
              substring = substring.to_bytes()
          return self._bytes.find(substringf find(self, substring):
          '''
          byte-like -> int
          Finds the index of substring
          '''
          if isinstance(substring, ByteData):
              substring = substring.to_bytes()
          return self._bytes.find(substring)
docs: byte-like -> int
          Finds the index of substring