code: def read_matrix(self):
      return _read_hb_data(self._fid, self._hb_info)
  
imports: import warnings
  import numpy
  from scipy.sparse import csc_matrix
  from ._fortran_format_parser import FortranFormatParser, IntFormat, ExpFormat
label_desc: Use image node_id 7 for calling the HBFile obj's underlying member method code with example usage: obj.read_matrix() and returns: _read_hb_data