""" Purpose: help with understanding that functions are first class
"""

def black() :
    print( "Black" )

def white() :
    print( "White" )

def go( f ) :
    """ Invokes the function indicated by parameter f
    """

    f()

if ( __name__ == "__main__" ) :

    go( black )  # go() run's function black
    go( print )  # go() run's function print
    go( white )  # go() run's function white