code: def get_default_kernel_type(domain_type):
      """Returns default kernel type for the domain."""
      if domain_type == "euclidean":
          return _DFLT_DOMAIN_EUC_KERNEL_TYPE
      elif domain_type == "discrete_euclidean":
          return _DFLT_DOMAIN_EUC_KERNEL_TYPE
      elif domain_type == "integral":
          return _DFLT_DOMAIN_INT_KERNEL_TYPE
      elif domain_type == "prod_discrete":
          return _DFLT_DOMAIN_DISCRETE_KERNEL_TYPE
      elif domain_type == "prod_discrete_numeric":
          return _DFLT_DOMAIN_DISCRETE_NUMERIC_KERNEL_TYPE
      elif domain_type == "neural_network":
          return _DFLT_DOMAIN_NN_KERNEL_TYPE
      else:
          raise ValueError("Unknown domain_type: %s." % (domain_type))
  
imports: from __future__ import print_function
  from argparse import Namespace
  import numpy
  from ..exd import domains
  from ..exd.cp_domain_utils import load_cp_domain_from_config_file
  from .None import gp_core, mf_gp
  from .euclidean_gp import get_euclidean_integral_gp_kernel_with_scale, prep_euclidean_integral_kernel_hyperparams
  from .kernel import CartesianProductKernel, HammingKernel
  from ..utils.general_utils import get_idxs_from_list_of_lists
  from ..utils.option_handler import get_option_specs, load_options
  from ..utils.reporters import get_reporter
label_desc: Use image node_id 1 for calling a global function with example usage: get_default_kernel_type(domain_type) and returns: _DFLT_DOMAIN_EUC_KERNEL_TYPE, _DFLT_DOMAIN_EUC_KERNEL_TYPE, _DFLT_DOMAIN_INT_KERNEL_TYPE, _DFLT_DOMAIN_DISCRETE_KERNEL_TYPE, _DFLT_DOMAIN_DISCRETE_NUMERIC_KERNEL_TYPE, _DFLT_DOMAIN_NN_KERNEL_TYPE