function streamChangedDocuments(rxCollection) {
  var prevFilter = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : function (_i) {
    return true;
  };
  if (!rxCollection._doNotEmitSet) rxCollection._doNotEmitSet = new Set();
  var observable = (0, _rxjs.fromEvent)(rxCollection.pouch.changes({
    since: 'now',
    live: true,
    include_docs: true
  }), 'change').pipe(
  /**
   * we need this delay because with pouchdb 7.2.2
   * it happened that _doNotEmitSet.add() from applyChangedDocumentToPouch()
   * was called after the change was streamed downwards
   * which then leads to a wrong detection
   */
  (0, _operators.delay)(0), (0, _operators.map)(function (changeAr) {
    return changeAr[0];
  }), // rxjs emits an array for whatever reason
  (0, _operators.filter)(function (change) {
    // changes on the doNotEmit-list shell not be fired
    var emitFlag = change.id + ':' + change.doc._rev;
    if (rxCollection._doNotEmitSet.has(emitFlag)) return false;else return true;
  }), (0, _operators.filter)(function (change) {
    return prevFilter(change);
  }), (0, _operators.map)(function (change) {
    return rxCollection._handleFromPouch(change.doc);
  }));
  return observable;
}
/**
 * returns an observable that streams all changes
 * as plain documents that have no encryption or keyCompression.
 * We use this to replicate changes from one collection to the other
 * @param prevFilter can be used to filter changes before doing anything
 * @return observable that emits document-data
 */
returns an observable that streams all changes
as plain documents that have no encryption or keyCompression.
We use this to replicate changes from one collection to the other
@param prevFilter can be used to filter changes before doing anything
@return observable that emits document-data
returns an observable that streams all changes as plain documents that have no encryption or keyCompression . We use this to replicate changes from one collection to the other @param prevFilter can be used to filter changes before doing anything @return observable that emits document - data
function streamChangedDocuments(rxCollection) {
  var prevFilter = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : function (_i) {
    return true;
  };
  if (!rxCollection._doNotEmitSet) rxCollection._doNotEmitSet = new Set();
  var observable = (0, _rxjs.fromEvent)(rxCollection.pouch.changes({
    since: 'now',
    live: true,
    include_docs: true
  }), 'change').pipe(
  (0, _operators.delay)(0), (0, _operators.map)(function (changeAr) {
    return changeAr[0];
  }), 
  (0, _operators.filter)(function (change) {
    var emitFlag = change.id + ':' + change.doc._rev;
    if (rxCollection._doNotEmitSet.has(emitFlag)) return false;else return true;
  }), (0, _operators.filter)(function (change) {
    return prevFilter(change);
  }), (0, _operators.map)(function (change) {
    return rxCollection._handleFromPouch(change.doc);
  }));
  return observable;
}
function streamChangedDocuments ( rxCollection ) { var prevFilter = arguments . length > 1 && arguments [ 1 ] !== undefined ? arguments [ 1 ] : function ( _i ) { return true ; } ; if ( ! rxCollection . _doNotEmitSet ) rxCollection . _doNotEmitSet = new Set ( ) ; var observable = ( 0 , _rxjs . fromEvent ) ( rxCollection . pouch . changes ( { since : 'now' , live : true , include_docs : true } ) , 'change' ) . pipe ( ( 0 , _operators . delay ) ( 0 ) , ( 0 , _operators . map ) ( function ( changeAr ) { return changeAr [ 0 ] ; } ) , ( 0 , _operators . filter ) ( function ( change ) { var emitFlag = change . id + ':' + change . doc . _rev ; if ( rxCollection . _doNotEmitSet . has ( emitFlag ) ) return false ; else return true ; } ) , ( 0 , _operators . filter ) ( function ( change ) { return prevFilter ( change ) ; } ) , ( 0 , _operators . map ) ( function ( change ) { return rxCollection . _handleFromPouch ( change . doc ) ; } ) ) ; return observable ; }
returns an observable that streams all changes
 as plain documents that have no encryption or keyCompression.
returns an observable that streams all changes as plain documents that have no encryption or keyCompression .
/**
   * we need this delay because with pouchdb 7.2.2
   * it happened that _doNotEmitSet.add() from applyChangedDocumentToPouch()
   * was called after the change was streamed downwards
   * which then leads to a wrong detection
   */ // rxjs emits an array for whatever reason // changes on the doNotEmit-list shell not be fired