class_docstr: Base test class for Multi-fidelity Optimisers on Cartesian Product Spaces. 
docstr: Instantiate the optimiser. 
docstr_tok: ["Instantiate","the","optimiser","."]
code: def _child_instantiate_optimiser(
      cls, func_caller, worker_manager, options, reporter
  ):
      """Instantiate the optimiser."""
      raise NotImplementedError("Implement in a child class.")
  
imports: import os
  import unittest
label_desc: Use image node_id 2 for calling the MFCPOptimiserBaseTestCase obj's underlying member method code with example usage: obj._child_instantiate_optimiser(cls, func_caller, worker_manager, options, reporter) without return types