code: def read_elastic_tensor(self):
          
          header_pattern = r"TOTAL ELASTIC MODULI \(kBar\)\s+" \
                           r"Direction\s+([X-Z][X-Z]\s+)+" \
                           r"\-+"
          row_pattern = r"[X-Z][X-Z]\s+" + r"\s+".join([r"(\-*[\.\d]+)"] * 6)
          footer_pattern = r"\-+"
          et_table = self.read_table_pattern(header_pattern, row_pattern,
                                             footer_pattern, postprocess=float)
          self.data["elastic_tensor"] = et_table
docs: Parse the elastic tensor data.
  
          Returns:
              6x6 array corresponding to the elastic tensor from the OUTCAR.