remove unused 'first' imports

src/app/+search-page/search-filters/search-filter/search-facet-filter/search-facet-filter.component.ts

@@ -6,7 +6,7 @@ import {
   Subject,
   Subscription
 } from 'rxjs';
-import { switchMap, distinctUntilChanged, first, map, take } from 'rxjs/operators';
+import { switchMap, distinctUntilChanged, map, take } from 'rxjs/operators';
 import { animate, state, style, transition, trigger } from '@angular/animations';
 import { Component, Inject, OnDestroy, OnInit } from '@angular/core';
 import { Router } from '@angular/router';

src/app/+search-page/search-filters/search-filter/search-filter.component.ts

@@ -1,5 +1,4 @@
-
+import { take } from 'rxjs/operators';
-import { first, take } from 'rxjs/operators';
 import { Component, Input, OnInit } from '@angular/core';
 import { SearchFilterConfig } from '../../search-service/search-filter-config.model';
 import { SearchFilterService } from './search-filter.service';

src/app/app.component.ts

@@ -1,4 +1,4 @@
-import { filter, first, map, take } from 'rxjs/operators';
+import { filter, map, take } from 'rxjs/operators';
 import {
   AfterViewInit,
   ChangeDetectionStrategy,

src/app/core/auth/auth.effects.ts

@@ -1,6 +1,6 @@
 import { of as observableOf, Observable } from 'rxjs';
 
-import { filter, debounceTime, switchMap, take, tap, catchError, map, first } from 'rxjs/operators';
+import { filter, debounceTime, switchMap, take, tap, catchError, map } from 'rxjs/operators';
 import { Injectable } from '@angular/core';
 
 // import @ngrx

src/app/core/auth/auth.service.ts

@@ -2,7 +2,6 @@ import { Observable, of as observableOf } from 'rxjs';
 import {
   distinctUntilChanged,
   filter,
-  first,
   map,
   startWith,
   switchMap,

src/app/core/auth/server-auth.service.ts

@@ -1,4 +1,4 @@
-import { first, map, switchMap, take } from 'rxjs/operators';
+import { map, switchMap, take } from 'rxjs/operators';
 import { Injectable } from '@angular/core';
 
 import { Observable } from 'rxjs';

src/app/core/cache/builders/remote-data-build.service.ts

@@ -7,7 +7,6 @@ import {
 import { Injectable } from '@angular/core';
 import {
   distinctUntilChanged,
-  first,
   flatMap,
   map,
   startWith,

src/app/core/cache/object-cache.service.ts

@@ -1,6 +1,6 @@
 import { combineLatest as observableCombineLatest, Observable } from 'rxjs';
 
-import { distinctUntilChanged, filter, first, map, mergeMap, take, } from 'rxjs/operators';
+import { distinctUntilChanged, filter, map, mergeMap, take, } from 'rxjs/operators';
 import { Injectable } from '@angular/core';
 import { MemoizedSelector, select, Store } from '@ngrx/store';
 import { IndexName } from '../index/index.reducer';

src/app/core/cache/server-sync-buffer.effects.ts

@@ -1,4 +1,4 @@
-import { delay, exhaustMap, first, map, switchMap, take, tap } from 'rxjs/operators';
+import { delay, exhaustMap, map, switchMap, take } from 'rxjs/operators';
 import { Inject, Injectable } from '@angular/core';
 import { Actions, Effect, ofType } from '@ngrx/effects';
 import {

src/app/core/data/data.service.ts

@@ -1,4 +1,4 @@
-import { delay, distinctUntilChanged, filter, find, first, map, take, tap } from 'rxjs/operators';
+import { filter, find, map, take } from 'rxjs/operators';
 import { Observable } from 'rxjs';
 import { Store } from '@ngrx/store';
 import { hasValue, isNotEmpty } from '../../shared/empty.util';
@@ -14,7 +14,6 @@ import { NormalizedObject } from '../cache/models/normalized-object.model';
 import { compare, Operation } from 'fast-json-patch';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { DSpaceObject } from '../shared/dspace-object.model';
-import { of } from 'rxjs/internal/observable/of';
 
 export abstract class DataService<TNormalized extends NormalizedObject, TDomain> {
   protected abstract requestService: RequestService;

src/app/core/metadata/metadata.service.ts

@@ -2,7 +2,6 @@ import {
   catchError,
   distinctUntilKeyChanged,
   filter,
-  find,
   first,
   map,
   take

src/app/core/shared/operators.ts

@@ -1,5 +1,5 @@
 import { Observable } from 'rxjs';
-import { filter, find, first, flatMap, map, tap } from 'rxjs/operators';
+import { filter, find, flatMap, map, tap } from 'rxjs/operators';
 import { hasValue, hasValueOperator, isNotEmpty } from '../../shared/empty.util';
 import { DSOSuccessResponse, RestResponse } from '../cache/response.models';
 import { RemoteData } from '../data/remote-data';