code: def check_multi_b(gtab, n_bvals, non_zero=True, bmag=None):
      """
      Check if you have enough different b-values in your gradient table
  
      Parameters
      ----------
      gtab : GradientTable class instance.
  
      n_bvals : int
          The number of different b-values you are checking for.
      non_zero : bool
          Whether to check only non-zero bvalues. In this case, we will require
          at least `n_bvals` *non-zero* b-values (where non-zero is defined
          depending on the `gtab` object's `b0_threshold` attribute)
      bmag : int
          The order of magnitude of the b-values used. The function will
          normalize the b-values relative $10^{bmag}$. Default: derive this
          value from the maximal b-value provided:
          $bmag=log_{10}(max(bvals)) - 1$.
  
      Returns
      -------
      bool : Whether there are at least `n_bvals` different b-values in the
      gradient table used.
      """
      bvals = gtab.bvals.copy()
      if non_zero:
          bvals = bvals[~gtab.b0s_mask]
  
      uniqueb = unique_bvals_magnitude(bvals, bmag=bmag)
      if uniqueb.shape[0] < n_bvals:
          return False
      else:
          return True
  
imports: import logging
  from warnings import warn
  import numpy
  from scipy.linalg import inv, polar
  from dipy.io import gradients
  from dipy.core.onetime import auto_attr
  from dipy.core.geometry import vector_norm, vec2vec_rotmat
  from dipy.core.sphere import disperse_charges, HemiSphere
  from dipy.utils.deprecator import deprecate_with_version
label_desc: Use image node_id 15 for calling a global function with example usage: check_multi_b(gtab, n_bvals, non_zero, bmag) and returns: False, True