code: def custom_properties(self, props):
          
          fprops = javabridge.make_instance("java/io/File", "(Ljava/lang/String;)V", props)
          javabridge.call(self.jobject, "setCustomPropsFile", "(Ljava/io/File;)V", fprops)
docs: Sets the custom properties file to use.
  
          :param props: the props file
          :type props: str