function getNonEmptyOperand(node) {
	return isEmptyString(node.left) ? node.right : node.left;
}
Returns the operand that is not an empty string from a flagged BinaryExpression.
@param {ASTNode} node The flagged BinaryExpression node to check.
@returns {ASTNode} The operand that is not an empty string from a flagged BinaryExpression.