How to use the @angular2-material/icon.MdIconModule.forRoot function in @angular2-material/icon

MdCheckboxModule.forRoot(),
        MdGridListModule.forRoot(),
        MdInputModule.forRoot(),
        MdListModule.forRoot(),
        MdProgressBarModule.forRoot(),
        MdProgressCircleModule.forRoot(),
        MdRippleModule.forRoot(),
        MdSidenavModule.forRoot(),
        MdTabsModule.forRoot(),
        MdToolbarModule.forRoot(),
        PortalModule.forRoot(),
        RtlModule.forRoot(),

        // These modules include providers.
        MdButtonToggleModule.forRoot(),
        MdIconModule.forRoot(),
        MdMenuModule.forRoot(),
        MdRadioModule.forRoot(),
        MdSliderModule.forRoot(),
        MdSlideToggleModule.forRoot(),
        MdTooltipModule.forRoot(),
        OverlayModule.forRoot(),
    ],
    exports: MATERIAL_MODULES,
    providers: [MdLiveAnnouncer]
})
export class MaterialRootModule {
}


@NgModule({
    imports: MATERIAL_MODULES,

import { PresetsService } from './services/presets.service';

// This imports the variable that, in a hot loading situation, holds
// a reference to the previous application's last state before
// it was destroyed.
import { appState } from '../hmr';

@NgModule({
  imports: [
    BrowserModule,
    ReactiveFormsModule, // Used by Angular 2 Material
    HttpModule, // Used by Angular 2 Material (to load icons, apparently?)
    StoreModule.provideStore(harmonicsReducer, appState), 
    EffectsModule,
    MdButtonModule,
    MdIconModule.forRoot(),
    MdSliderModule
  ],
  declarations: [
    AppComponent,
    ContainerComponent,
    MainMenuComponent,
    CurveComponent, 
    GainInputComponent,
    MuteControlComponent,
    NoteControlComponent,
    PartialComponent,
    TotalComponent
  ],
  providers: [
    AudioService,
    NoteService,

import { NgModule } from '@angular/core';

import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { CommonModule } from '@angular/common';

import { MdInputModule } from '@angular2-material/input';
import { MdIconModule } from '@angular2-material/icon';

@NgModule({
  imports: [
    BrowserModule,
    FormsModule,
    CommonModule,
    MdInputModule.forRoot(),
    MdIconModule.forRoot(),
  ],
  declarations: [
    TdChipsComponent,
    TdChipComponent,
    TdAutoCompleteComponent,
  ],
  exports: [
    TdChipsComponent,
    TdChipComponent,
    TdAutoCompleteComponent,
  ],
})
export class CovalentChipsModule {
}

MdInputModule,
    MdButtonModule,
    MdIconModule
];

@NgModule({
    imports: [
        MdCoreModule.forRoot(),
        MdSidenavModule.forRoot(),
        MdListModule.forRoot(),
        MdToolbarModule.forRoot(),
        MdCardModule.forRoot(),
        MdRadioModule.forRoot(),
        MdInputModule.forRoot(),
        MdButtonModule.forRoot(),
        MdIconModule.forRoot()
    ],
    exports: MATERIAL_MODULES
})

export class MaterialModule { }

export { TdJsonFormatterComponent } from './json-formatter.component';
import { TdJsonFormatterComponent } from './json-formatter.component';

import { NgModule } from '@angular/core';

import { BrowserModule } from '@angular/platform-browser';
import { CommonModule } from '@angular/common';

import { MdIconModule } from '@angular2-material/icon';

@NgModule({
  imports: [
    BrowserModule,
    CommonModule,
    MdIconModule.forRoot(),
  ],
  declarations: [
    TdJsonFormatterComponent,
  ],
  exports: [
    TdJsonFormatterComponent,
  ],
})
export class CovalentJsonFormatterModule {
}