docstr: Check whether x lies in the support of the distribution.
docstr_tok: ["Check","whether","x","lies","in","the","support","of","the","distribution","."]
code: def _support_mask(self, x):
      """
      Check whether x lies in the support of the distribution.
      """
      residual = np.linalg.norm(x @ self._null_basis, axis=-1)
      in_support = residual < self._eps
      return in_support
  
imports: from functools import cached_property
  import numpy
  from scipy import linalg
  from scipy.stats import _multivariate
label_desc: Use image node_id 5 for calling the CovViaEigendecomposition obj's underlying member method code with example usage: obj._support_mask(x) and returns: in_support