function validate( node ) {
		var scope;
		var name;
		var i;

		// Skip when the identifier refers to the key of an object:
		if ( node.parent.type === 'MemberExpression' ) {
			return void 0;
		}

		scope = context.getScope( node );
		for ( i = 0; i < opts.globals.length; i++ ) {
			name = opts.globals[ i ];
			if ( node.name === name ) {
				if ( !searchScopes( scope, name ) ) {
					report( node, name );
				}
				break;
			}
		}
	}
Checks whether a global is loaded via `require()` before invocation.

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