docs: public void marshall(PhoneNumberCapabilities phoneNumberCapabilities, ProtocolMarshaller protocolMarshaller) {
  
          if (phoneNumberCapabilities == null) {
              throw new SdkClientException("Invalid argument passed to marshall(...)");
          }
  
          try {
              protocolMarshaller.marshall(phoneNumberCapabilities.getInboundCall(), INBOUNDCALL_BINDING);
              protocolMarshaller.marshall(phoneNumberCapabilities.getOutboundCall(), OUTBOUNDCALL_BINDING);
              protocolMarshaller.marshall(phoneNumberCapabilities.getInboundSMS(), INBOUNDSMS_BINDING);
              protocolMarshaller.marshall(phoneNumberCapabilities.getOutboundSMS(), OUTBOUNDSMS_BINDING);
              protocolMarshaller.marshall(phoneNumberCapabilities.getInboundMMS(), INBOUNDMMS_BINDING);
              protocolMarshaller.marshall(phoneNumberCapabilities.getOutboundMMS(), OUTBOUNDMMS_BINDING);
          } catch (Exception e) {
              throw new SdkClientException("Unable to marshall request to JSON: " + e.getMessage(), e);
          }
      }