#NEWLINE# def test_from_node_callback_selector( self ) : #NEWLINE# #INDENT# res = Observable . from_callback ( ( lambda f , s , t , cb : cb ( f , s , t ) ) , ( lambda r : r [ 0 ] ) ) ( 1 , 2 , 3 ) #NEWLINE# def on_next( r ) : #NEWLINE# #INDENT# self . assertEqual ( r , 1 ) #NEWLINE# #UNINDENT# def on_error( err ) : #NEWLINE# #INDENT# assert False #NEWLINE# #UNINDENT# def on_completed( ) : #NEWLINE# #INDENT# assert True #NEWLINE# #UNINDENT# res . subscribe ( on_next , on_error , on_completed )