How to use the psyclone.psyir.nodes.BinaryOperation.Operator function in PSyclone

:returns: the SIR Python code.
        :rtype: str

        :raises VisitorError: if there is no mapping from the PSyIR \
        operator to SIR.

        '''
        binary_operators = {
            BinaryOperation.Operator.ADD: '+',
            BinaryOperation.Operator.SUB: '-',
            BinaryOperation.Operator.MUL: '*',
            BinaryOperation.Operator.DIV: '/',
            BinaryOperation.Operator.POW: '**',
            BinaryOperation.Operator.EQ: '==',
            BinaryOperation.Operator.NE: '!=',
            BinaryOperation.Operator.LE: '<=',
            BinaryOperation.Operator.LT: '<',
            BinaryOperation.Operator.GE: '>=',
            BinaryOperation.Operator.GT: '>',
            BinaryOperation.Operator.AND: '&&',
            BinaryOperation.Operator.OR: '||'}

        self._depth += 1
        lhs = self._visit(node.children[0])
        try:
            oper = binary_operators[node.operator]
        except KeyError:
            raise VisitorError(
                "Method binaryoperation_node in class SIRWriter, unsupported "
                "operator '{0}' found.".format(str(node.operator)))
        rhs = self._visit(node.children[1])

('log', UnaryOperation.Operator.LOG),
        ('log10', UnaryOperation.Operator.LOG10),
        ('sin', UnaryOperation.Operator.SIN),
        ('asin', UnaryOperation.Operator.ASIN),
        ('cos', UnaryOperation.Operator.COS),
        ('acos', UnaryOperation.Operator.ACOS),
        ('tan', UnaryOperation.Operator.TAN),
        ('atan', UnaryOperation.Operator.ATAN),
        ('sqrt', UnaryOperation.Operator.SQRT),
        ('real', UnaryOperation.Operator.REAL),
        ('int', UnaryOperation.Operator.INT)])

    binary_operators = OrderedDict([
        ('+', BinaryOperation.Operator.ADD),
        ('-', BinaryOperation.Operator.SUB),
        ('*', BinaryOperation.Operator.MUL),
        ('/', BinaryOperation.Operator.DIV),
        ('**', BinaryOperation.Operator.POW),
        ('==', BinaryOperation.Operator.EQ),
        ('.eq.', BinaryOperation.Operator.EQ),
        ('/=', BinaryOperation.Operator.NE),
        ('.ne.', BinaryOperation.Operator.NE),
        ('<=', BinaryOperation.Operator.LE),
        ('.le.', BinaryOperation.Operator.LE),
        ('<', BinaryOperation.Operator.LT),
        ('.lt.', BinaryOperation.Operator.LT),
        ('>=', BinaryOperation.Operator.GE),
        ('.ge.', BinaryOperation.Operator.GE),
        ('>', BinaryOperation.Operator.GT),
        ('.gt.', BinaryOperation.Operator.GT),
        ('.and.', BinaryOperation.Operator.AND),
        ('.or.', BinaryOperation.Operator.OR),

:param int index: the array index to check.

        :returns: True if the array index is a range with its start \
            value being LBOUND(array,index) and False otherwise.
        :rtype: bool

        '''
        self._validate_index(index)

        array_dimension = self.children[index]
        if not isinstance(array_dimension, Range):
            return False

        lower = array_dimension.children[0]
        if not (isinstance(lower, BinaryOperation) and
                lower.operator == BinaryOperation.Operator.LBOUND):
            return False
        if not (isinstance(lower.children[0], Reference) and
                lower.children[0].name == self.name):
            return False
        if not (isinstance(lower.children[1], Literal) and
                lower.children[1].datatype.intrinsic ==
                ScalarType.Intrinsic.INTEGER
                and lower.children[1].value == str(index+1)):
            return False
        return True

(BinaryOperation, BinaryOperation, Literal)

    :raises TransformationError: if the shape of the array's symbol is \
        not supported.

    '''
    my_dim = array.symbol.shape[index]
    if isinstance(my_dim, int):
        lower_bound = Literal("1", INTEGER_TYPE)
        upper_bound = Literal(str(my_dim), INTEGER_TYPE)
    elif isinstance(my_dim, DataSymbol):
        lower_bound = Literal("1", INTEGER_TYPE)
        upper_bound = Reference(my_dim)
    elif my_dim in [ArrayType.Extent.DEFERRED, ArrayType.Extent.ATTRIBUTE]:
        lower_bound = BinaryOperation.create(
            BinaryOperation.Operator.LBOUND, Reference(array.symbol),
            Literal(str(index), INTEGER_TYPE))
        upper_bound = BinaryOperation.create(
            BinaryOperation.Operator.UBOUND, Reference(array.symbol),
            Literal(str(index), INTEGER_TYPE))
    else:
        # Added import here to avoid circular dependencies.
        from psyclone.psyir.transformations import TransformationError
        raise TransformationError(
            "Unsupported index type '{0}' found for dimension {1} of array "
            "'{2}'.".format(type(my_dim).__name__, index+1, array.name))
    step = Literal("1", INTEGER_TYPE)
    return (lower_bound, upper_bound, step)

('ceiling', UnaryOperation.Operator.CEIL),
        ('exp', UnaryOperation.Operator.EXP),
        ('log', UnaryOperation.Operator.LOG),
        ('log10', UnaryOperation.Operator.LOG10),
        ('sin', UnaryOperation.Operator.SIN),
        ('asin', UnaryOperation.Operator.ASIN),
        ('cos', UnaryOperation.Operator.COS),
        ('acos', UnaryOperation.Operator.ACOS),
        ('tan', UnaryOperation.Operator.TAN),
        ('atan', UnaryOperation.Operator.ATAN),
        ('sqrt', UnaryOperation.Operator.SQRT),
        ('real', UnaryOperation.Operator.REAL),
        ('int', UnaryOperation.Operator.INT)])

    binary_operators = OrderedDict([
        ('+', BinaryOperation.Operator.ADD),
        ('-', BinaryOperation.Operator.SUB),
        ('*', BinaryOperation.Operator.MUL),
        ('/', BinaryOperation.Operator.DIV),
        ('**', BinaryOperation.Operator.POW),
        ('==', BinaryOperation.Operator.EQ),
        ('.eq.', BinaryOperation.Operator.EQ),
        ('/=', BinaryOperation.Operator.NE),
        ('.ne.', BinaryOperation.Operator.NE),
        ('<=', BinaryOperation.Operator.LE),
        ('.le.', BinaryOperation.Operator.LE),
        ('<', BinaryOperation.Operator.LT),
        ('.lt.', BinaryOperation.Operator.LT),
        ('>=', BinaryOperation.Operator.GE),
        ('.ge.', BinaryOperation.Operator.GE),
        ('>', BinaryOperation.Operator.GT),
        ('.gt.', BinaryOperation.Operator.GT),

def __init__(self):
        super(NemoSignTrans, self).__init__()
        self._operator_name = "SIGN"
        self._classes = (BinaryOperation,)
        self._operators = (BinaryOperation.Operator.SIGN,)

:param my_range: the Range node to check.
    :type my_range: :py:class:`psyclone.psyir.node.Range`

    '''

    array = my_range.parent
    # The array index of this range is determined by its position in
    # the array list (+1 as the index starts from 0 but Fortran
    # dimensions start from 1).
    dim = array.children.index(my_range) + 1
    # Check lower bound
    is_lower = _is_bound_full_extent(
        array, dim, BinaryOperation.Operator.LBOUND)
    # Check upper bound
    is_upper = _is_bound_full_extent(
        array, dim, BinaryOperation.Operator.UBOUND)
    # Check step (index 2 is the step index for the range function)
    is_step = _is_array_range_literal(array, dim, 2, 1)
    return is_lower and is_upper and is_step

:param int index: the array index to check.

        :returns: True if the array index is a range with its stop \
            value being UBOUND(array,index) and False otherwise.
        :rtype: bool

        '''
        self._validate_index(index)

        array_dimension = self.children[index]
        if not isinstance(array_dimension, Range):
            return False

        upper = array_dimension.children[1]
        if not (isinstance(upper, BinaryOperation) and
                upper.operator == BinaryOperation.Operator.UBOUND):
            return False
        if not (isinstance(upper.children[0], Reference) and
                upper.children[0].name == self.name):
            return False
        if not (isinstance(upper.children[1], Literal) and
                upper.children[1].datatype.intrinsic ==
                ScalarType.Intrinsic.INTEGER
                and upper.children[1].value == str(index+1)):
            return False
        return True