code: def tensor_via_op(self, summary_op):
      actual_pbtxt = summary_op.eval()
      actual_proto = summary_pb2.Summary()
      actual_proto.ParseFromString(actual_pbtxt)
      return actual_proto
  
imports: import numpy
  import tensorflow
  from tensorboard.compat.proto import summary_pb2
  from tensorboard.plugins.pr_curve import metadata
  from tensorboard.plugins.pr_curve import summary
  from tensorboard.util import tensor_util
  from tensorboard.util import test_util
label_desc: Use image node_id 3 for calling the StreamingOpTest obj's underlying member method code with example usage: obj.tensor_via_op(summary_op) and returns: actual_proto