public Builder setFilter(java.lang.String value) {
      if (value == null) {
        throw new NullPointerException();
      }
      filter_ = value;
      bitField0_ |= 0x00000008;
      onChanged();
      return this;
    }
<pre>
A filter expression that matches resources returned in the response.
Currently, only filtering on the `direction` field is supported. To return
routes imported from the peer network, provide "direction=INCOMING". To
return routes exported from the VMware Engine network, provide
"direction=OUTGOING". Other filter expressions return an error.
</pre>

<code>string filter = 6;</code>

@param value The filter to set.
@return This builder for chaining.
java-vmwareengine/proto-google-cloud-vmwareengine-v1/src/main/java/com/google/cloud/vmwareengine/v1/ListPeeringRoutesRequest.java