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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def generate(str, alg):
 """Generates an PIL image avatar based on the given input String. Acts as the main accessor to pagan."""

    img = Image.new(IMAGE_MODE, IMAGE_SIZE, BACKGROUND_COLOR)
    hashcode = hash_input(str, alg)
    pixelmap = setup_pixelmap(hashcode)
    draw_image(pixelmap, img)
    return img