code: function() {
  			if (this._oFilterExpression == null) {
  				var oEntityType = this._oEntitySet.getEntityType();
  				var oModel = this._oDimension.getContainingQueryResult().getModel();
  				this._oFilterExpression = new odata4analytics.FilterExpression(oModel, oEntityType
  						.getSchema(), oEntityType);
  			}
  			return this._oFilterExpression;
  		}
docs: Get the filter expression for this request.
  
  Expressions are represented by separate objects. If none exists so far, a
  new expression object gets created.
  
  @returns {sap.ui.model.analytics.odata4analytics.FilterExpression} The filter object
  associated to this request.
  @public
  @function
  @name sap.ui.model.analytics.odata4analytics.DimensionMemberSetRequest#getFilterExpression