class_docstr: Simple OPF client.
  
  :param modelConfig: (dict) The model config.
  :param metricSpecs: A sequence of
         :class:`~nupic.frameworks.opf.metrics.MetricSpec` instances.
  :param sourceSpec: (string) Path to the source CSV file.
  :param sinkSpec: (string) Path to the sink CSV file.
code: def next(self):
      record = self.datasetReader.next()
      return self._processRecord(record)
  
file_path: nupic-legacy/src/nupic/frameworks/opf/client.py
imports: from nupic.frameworks.opf.model_factory import ModelFactory
  from nupic.frameworks.opf.opf_basic_environment import BasicDatasetReader
  from nupic.frameworks.opf.prediction_metrics_manager import MetricsManager
label_desc: Use image node_id 4 for calling the Client obj's underlying member method code with example usage: obj.next() and returns: self