#NEWLINE# def add_child_hash( self , child_hash ) : #NEWLINE# #INDENT# '\n        Adds specified child hash.\n\n        The hash must be one of the binary types.\n        ' #NEWLINE# if ( not ( isinstance ( self , PCABinaryProjections ) or isinstance ( child_hash , RandomBinaryProjections ) or isinstance ( child_hash , RandomBinaryProjectionTree ) ) ) : #NEWLINE# #INDENT# raise ValueError ( 'Child hashes must generate binary keys' ) #NEWLINE# #UNINDENT# self . child_hashes . append ( child_hash )