code: @SuppressWarnings({ "unchecked", "rawtypes" })
  	@Override
  	public RequestBody convert(T value) throws IOException {
  		Buffer buffer = new Buffer();	
  		
  		try {	
  			binderContext.serializeCollection((Collection) value, (Class)clazz,buffer.outputStream()); 			
  			return RequestBody.create(MEDIA_TYPE, buffer.readByteString());
  		} catch (Exception e) {			
  			e.printStackTrace();
  			return null;
  		} finally
  		{
  			buffer.close();
  		}
  		
  		
  	}
docs: /* (non-Javadoc)
  @see retrofit2.Converter#convert(java.lang.Object)