docstr: True if array has NaNs
docstr_tok: ["True","if","array","has","NaNs"]
code: def has_nan(self):
      """True if array has NaNs"""
      # Structured types raise an error for finite range; don't run finite
      # range unless we have to.
      if self._has_nan is None:
          if self._array.dtype.kind in "fc":
              self.finite_range()
          else:
              self._has_nan = False
      return self._has_nan
  
imports: import numpy
  from .casting import best_float, floor_exact, int_abs, shared_range, type_info
  from .volumeutils import array_to_file, finite_range
label_desc: Use image node_id 5 for calling the ArrayWriter obj's underlying member method code with example usage: obj.has_nan() and returns: self