<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def blob( self, blob_name, chunk_size=None, encryption_key=None, kms_key_name=None, generation=None, ):
 """Factory constructor for blob object. .. note:: This will not make an HTTP request; it simply instantiates a blob object owned by this bucket. :type blob_name: str :param blob_name: The name of the blob to be instantiated. :type chunk_size: int :param chunk_size: The size of a chunk of data whenever iterating (in bytes). This must be a multiple of 256 KB per the API specification. :type encryption_key: bytes :param encryption_key: Optional 32 byte encryption key for customer-supplied encryption. :type kms_key_name: str :param kms_key_name: Optional resource name of KMS key used to encrypt blob's content. :type generation: long :param generation: Optional. If present, selects a specific revision of this object. :rtype: :class:`google.cloud.storage.blob.Blob` :returns: The blob object created. """

        return Blob(
            name=blob_name,
            bucket=self,
            chunk_size=chunk_size,
            encryption_key=encryption_key,
            kms_key_name=kms_key_name,
            generation=generation,
        )