How to use the astor.op_util.get_op_symbol function in astor

def visit_UnaryOp(self, node):
        with self.delimit(node, node.op) as delimiters:
            set_precedence(delimiters.p, node.operand)
            # In Python 2.x, a unary negative of a literal
            # number is merged into the number itself.  This
            # bit of ugliness means it is useful to know
            # what the parent operation was...
            node.operand._p_op = node.op
            sym = get_op_symbol(node.op)
            self.write(sym, ' ' if sym.isalpha() else '', node.operand)

def visit_BinOp(self, node):
        op, left, right = node.op, node.left, node.right
        with self.delimit(node, op) as delimiters:
            ispow = isinstance(op, ast.Pow)
            p = delimiters.p
            set_precedence((Precedence.Pow + 1) if ispow else p, left)
            set_precedence(Precedence.PowRHS if ispow else (p + 1), right)
            self.write(left, get_op_symbol(op, ' %s '), right)

def visit_BoolOp(self, node):
        with self.delimit(node, node.op) as delimiters:
            op = get_op_symbol(node.op, ' %s ')
            set_precedence(delimiters.p + 1, *node.values)
            for idx, value in enumerate(node.values):
                self.write(idx and op or '', value)

def visit_Compare(self, node):
        with self.delimit(node, node.ops[0]) as delimiters:
            set_precedence(delimiters.p + 1, node.left, *node.comparators)
            self.visit(node.left)
            for op, right in zip(node.ops, node.comparators):
                self.write(get_op_symbol(op, ' %s '), right)

def visit_AugAssign(self, node):
        set_precedence(node, node.value, node.target)
        self.statement(node, node.target, get_op_symbol(node.op, ' %s= '),
                       node.value)