How to use the angular2/src/facade/lang.isPresent function in angular2

_runValidator() {
        return isPresent(this.validator) ? this.validator(this) : null;
    }
    _runAsyncValidator(emitEvent) {

private _isValidAttributeValue(attrName: string, value: any): boolean {
    if (attrName == "role") {
      return isString(value);
    } else {
      return isPresent(value);
    }
  }

function getStylesVarName(component) {
    var result = "styles";
    if (lang_1.isPresent(component)) {
        result += "_" + component.type.name;
    }
    return result;
}
//# 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{\n  CompileTemplateMetadata,\n  CompileIdentifierMetadata,\n  CompileDirectiveMetadata\n} from './compile_metadata';\nimport * as o from './output/output_ast';\nimport {ViewEncapsulation} from 'angular2/src/core/metadata/view';\nimport {ShadowCss} from 'angular2/src/compiler/shadow_css';\nimport {UrlResolver} from 'angular2/src/compiler/url_resolver';\nimport {extractStyleUrls} from './style_url_resolver';\nimport {Injectable} from 'angular2/src/core/di';\nimport {isPresent} from 'angular2/src/facade/lang';\n\nconst COMPONENT_VARIABLE = '%COMP%';\nconst HOST_ATTR = `_nghost-${COMPONENT_VARIABLE}`;\nconst CONTENT_ATTR = `_ngcontent-${COMPONENT_VARIABLE}`;\n\nexport class StylesCompileDependency {\n  constructor(public sourceUrl: string, public isShimmed: boolean,\n              public valuePlaceholder: CompileIdentifierMetadata) {}\n}\n\nexport class StylesCompileResult {\n  constructor(public statements: o.Statement[], public stylesVar: string,\n              public dependencies: StylesCompileDependency[]) {}\n}\n\n@Injectable()\nexport class StyleCompiler {\n  private _shadowCss: ShadowCss = new ShadowCss();\n\n  constructor(private _urlResolver: UrlResolver) {}\n\n  compileComponent(comp: CompileDirectiveMetadata): StylesCompileResult {\n    var shim = comp.template.encapsulation === ViewEncapsulation.Emulated;\n    return this._compileStyles(getStylesVarName(comp), comp.template.styles,\n                               comp.template.styleUrls, shim);\n  }\n\n  compileStylesheet(stylesheetUrl: string, cssText: string,\n                    isShimmed: boolean): StylesCompileResult {\n    var styleWithImports = extractStyleUrls(this._urlResolver, stylesheetUrl, cssText);\n    return this._compileStyles(getStylesVarName(null), [styleWithImports.style],\n                               styleWithImports.styleUrls, isShimmed);\n  }\n\n  private _compileStyles(stylesVar: string, plainStyles: string[], absUrls: string[],\n                         shim: boolean): StylesCompileResult {\n    var styleExpressions =\n        plainStyles.map(plainStyle => o.literal(this._shimIfNeeded(plainStyle, shim)));\n    var dependencies = [];\n    for (var i = 0; i < absUrls.length; i++) {\n      var identifier = new CompileIdentifierMetadata({name: getStylesVarName(null)});\n      dependencies.push(new StylesCompileDependency(absUrls[i], shim, identifier));\n      styleExpressions.push(new o.ExternalExpr(identifier));\n    }\n    // styles variable contains plain strings and arrays of other styles arrays (recursive),\n    // so we set its type to dynamic.\n    var stmt = o.variable(stylesVar)\n                   .set(o.literalArr(styleExpressions,\n                                     new o.ArrayType(o.DYNAMIC_TYPE, [o.TypeModifier.Const])))\n                   .toDeclStmt(null, [o.StmtModifier.Final]);\n    return new StylesCompileResult([stmt], stylesVar, dependencies);\n  }\n\n  private _shimIfNeeded(style: string, shim: boolean): string {\n    return shim ? this._shadowCss.shimCssText(style, CONTENT_ATTR, HOST_ATTR) : style;\n  }\n}\n\nfunction getStylesVarName(component: CompileDirectiveMetadata): string {\n  var result = `styles`;\n  if (isPresent(component)) {\n    result += `_${component.type.name}`;\n  }\n  return result;\n}"]}

_createDirectiveHostEventAsts(hostListeners, sourceSpan, targetEventAsts) {
        if (isPresent(hostListeners)) {
            StringMapWrapper.forEach(hostListeners, (expression, propName) => {
                this._parseEvent(propName, expression, sourceSpan, [], targetEventAsts);
            });
        }
    }
    _createDirectivePropertyAsts(directiveProperties, boundProps, targetBoundDirectiveProps) {

function matchUrlQueryParamValue(str) {
    var match = lang_1.RegExpWrapper.firstMatch(QUERY_PARAM_VALUE_RE, str);
    return lang_1.isPresent(match) ? match[0] : '';
}
var UrlParser = (function () {

var providerValueExpressions = resolvedProvider.providers.map((provider) => {
                if (isPresent(provider.useExisting)) {
                    return this._getDependency(resolvedProvider.providerType, new CompileDiDependencyMetadata({ token: provider.useExisting }));
                }
                else if (isPresent(provider.useFactory)) {
                    var deps = isPresent(provider.deps) ? provider.deps : provider.useFactory.diDeps;
                    var depsExpr = deps.map((dep) => this._getDependency(resolvedProvider.providerType, dep));
                    return o.importExpr(provider.useFactory).callFn(depsExpr);
                }
                else if (isPresent(provider.useClass)) {
                    var deps = isPresent(provider.deps) ? provider.deps : provider.useClass.diDeps;
                    var depsExpr = deps.map((dep) => this._getDependency(resolvedProvider.providerType, dep));
                    return o.importExpr(provider.useClass)
                        .instantiate(depsExpr, o.importType(provider.useClass));
                }
                else {
                    if (provider.useValue instanceof CompileIdentifierMetadata) {
                        return o.importExpr(provider.useValue);
                    }
                    else if (provider.useValue instanceof o.Expression) {
                        return provider.useValue;

function mergeOptions(defaultOpts, providedOpts, method, url) {
    var newOptions = defaultOpts;
    if (lang_1.isPresent(providedOpts)) {
      return newOptions.merge(new base_request_options_1.RequestOptions({
        method: providedOpts.method || method,
        url: providedOpts.url || url,
        search: providedOpts.search,
        headers: providedOpts.headers,
        body: providedOpts.body
      }));
    }
    if (lang_1.isPresent(method)) {
      return newOptions.merge(new base_request_options_1.RequestOptions({
        method: method,
        url: url
      }));
    } else {
      return newOptions.merge(new base_request_options_1.RequestOptions({url: url}));
    }
  }
  var Http = (function() {

destroy() {
        if (this._hasExternalHostElement) {
            this.renderer.detachView(this.flatRootNodes);
        }
        else if (isPresent(this.viewContainerElement)) {
            this.viewContainerElement.detachView(this.viewContainerElement.nestedViews.indexOf(this));
        }
        this._destroyRecurse();
    }
    _destroyRecurse() {

DomRenderer.prototype.createElement = function (parent, name, debugInfo) {
        var nsAndName = splitNamespace(name);
        var el = lang_1.isPresent(nsAndName[0]) ?
            dom_adapter_1.DOM.createElementNS(NAMESPACE_URIS[nsAndName[0]], nsAndName[1]) :
            dom_adapter_1.DOM.createElement(nsAndName[1]);
        if (lang_1.isPresent(this._contentAttr)) {
            dom_adapter_1.DOM.setAttribute(el, this._contentAttr, '');
        }
        if (lang_1.isPresent(parent)) {
            dom_adapter_1.DOM.appendChild(parent, el);
        }
        return el;
    };
    DomRenderer.prototype.createViewRoot = function (hostElement) {

_pruneQueryFromTree(query: QueryRef) {
    this._removeQueryRef(query);

    var child = this._head;
    while (isPresent(child)) {
      child._pruneQueryFromTree(query);
      child = child._next;
    }
  }