code: def load_sdp_constraints(model_name, order=None):
      """Import semidefinite programming constraint matrices for different models,
      generated as described for example in [1]_.
  
      Parameters
      ----------
      model_name : string
          A string identifying the model that is to be constrained.
      order : unsigned int, optional
          A non-negative integer that represent the order or instance of the
          model.
          Default: None.
  
      Returns
      -------
      sdp_constraints : array
          Constraint matrices
  
      Notes
      -----
      The constraints will be loaded from a file named 'id_constraint_order.npz'.
  
      References
      ----------
      .. [1] Dela Haije et al. "Enforcing necessary non-negativity constraints
             for common diffusion MRI models using sum of squares programming".
             NeuroImage 209, 2020, 116405.
  
      """
  
      file = model_name + "_constraint"
      if order is not None:
          file += "_" + str(order)
      file += ".npz"
      path = pjoin(DATA_DIR, file)
  
      if not exists(path):
          raise ValueError("Constraints file '" + file + "' not found.")
  
      try:
          array = load_npz(path)
          n, x = array.shape
          sdp_constraints = [
              array[i * x : (i + 1) * x] for i in range(n // x)
          ]
          return sdp_constraints
      except Exception:
          raise ValueError(
              "Failed to read constraints file '" + file + "'."
          )
  
imports: import json
  import pickle
  from os.path import join, dirname, exists
  import gzip
  import numpy
  from scipy.sparse import load_npz
  from dipy.core.gradients import GradientTable, gradient_table
  from dipy.core.sphere import Sphere, HemiSphere
  from dipy.data.fetcher import get_fnames, fetch_scil_b0, read_scil_b0, fetch_stanford_hardi, read_stanford_hardi, fetch_stanford_tracks, fetch_taiwan_ntu_dsi, read_taiwan_ntu_dsi, fetch_sherbrooke_3shell, read_sherbrooke_3shell, fetch_isbi2013_2shell, read_isbi2013_2shell, read_stanford_labels, fetch_stanford_labels, fetch_syn_data, read_syn_data, fetch_stanford_t1, read_stanford_t1, fetch_stanford_pve_maps, read_stanford_pve_maps, fetch_bundles_2_subjects, read_bundles_2_subjects, fetch_cenir_multib, read_cenir_multib, fetch_mni_template, read_mni_template, fetch_ivim, read_ivim, fetch_tissue_data, read_tissue_data, fetch_cfin_multib, read_cfin_dwi, read_cfin_t1, fetch_target_tractogram_hcp, fetch_bundle_atlas_hcp842, get_bundle_atlas_hcp842, get_target_tractogram_hcp, get_two_hcp842_bundles, fetch_bundle_fa_hcp, fetch_gold_standard_io, fetch_resdnn_weights, fetch_synb0_weights, fetch_synb0_test, fetch_evac_weights, fetch_evac_test, read_qte_lte_pte, read_DiB_70_lte_pte_ste, read_DiB_217_lte_pte_ste, read_five_af_bundles, fetch_hbn, fetch_ptt_minimal_dataset, fetch_bundle_warp_dataset
  from ..utils.arrfuncs import as_native_array
  from dipy.io.image import load_nifti
  from dipy.tracking.streamline import relist_streamlines
label_desc: Use image node_id 12 for calling a global function with example usage: load_sdp_constraints(model_name, order) and returns: sdp_constraints