Complete the code to produce "blue wolf" as an output.
class pencil:
color = 'yellow'
hardness = 2
class pencilCase:
def __init__(self, color, art):
self.color = color
self.art = art
def __str__(self):
return self.color + " " + self.art
# main program
pencilA = pencil() _____

print (caseA)