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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 visit_USR(self, node):
 """ Machine code call from basic """

        self.emit('fparam' + self.TSUFFIX(gl.PTR_TYPE), node.children[0].t)
        self.emit('call', 'USR', node.type_.size)
        backend.REQUIRES.add('usr.asm')