class_docstr: String representation of the data at every tick
class_docstr_tok: ["String","representation","of","the","data","at","every","tick"]
code: def __call__(self, x, pos=None):
      if pos is None:
          return ""
      r_mapping = {
          v: StrCategoryFormatter._text(k)
          for k, v in self._units.items()
      }
      return r_mapping.get(int(np.round(x)), "")
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from collections import OrderedDict
  import itertools
  import six
  import numpy
  import matplotlib.units
  import matplotlib.ticker
  from distutils.version import LooseVersion
label_desc: Use image node_id 2 for calling the StrCategoryFormatter obj's underlying member method code with example usage: obj.__call__(x, pos) and returns: r_mapping, str