class_docstr: `RosenBrock function <http://infinity77.net/global_optimization/test_functions_nd_R.html#go_benchmark.Rosenbrock>`_
  as benchmark task
docstr: Evaluate a n-D rosenbrock function.
docstr_tok: ["Evaluate","a","n-D","rosenbrock","function","."]
code: def call(self, x):
      """Evaluate a n-D rosenbrock function."""
      x = numpy.asarray(x)
      summands = 100 * (x[1:] - x[:-1] ** 2) ** 2 + (1 - x[:-1]) ** 2
      y = numpy.sum(summands)
      return [dict(name="rosenbrock", type="objective", value=y)]
  
imports: import numpy
  from orion.benchmark.task.base import BenchmarkTask
label_desc: Use image node_id 2 for calling the RosenBrock obj's underlying member method code with example usage: obj.call(x) and returns: list