function validate( node ) {
		var requirePath;
		if (
			node.callee.name === 'require' &&
			node.arguments[ 0 ] &&
			node.arguments[ 0 ].type === 'Literal'
		) {
			requirePath = node.arguments[ 0 ].value;
			requires.push({
				'node': node,
				'path': requirePath,
				'isRelative': isRelativePath( requirePath )
			});
		}
	}
Validates `require` statements.

@private
@param {ASTNode} node - node to examine