code: def load_fam(self, pheno_covar=None):
          
          logging.info("Loading file: %s" % (self.fam_file))
          pheno_col = 5
          if not DataParser.has_sex:
              pheno_col -= 1
          if not DataParser.has_parents:
              pheno_col -= 2
          if not DataParser.has_fid:
              pheno_col -= 1
  
          sex_col = pheno_col - 1
          mask_components = []
          for line in open(self.fam_file):
              words = line.strip().split()
              if len(words) > 1:
                  indid = ":".join(words[0:2])
                  if DataParser.valid_indid(indid):
                      mask_components.append(0)
  
                      sex = None
                      pheno = None
                      if DataParser.has_sex:
                          sex = int(words[sex_col])
                      if DataParser.has_pheno:
                          pheno = float(words[pheno_col])
                      if pheno_covar is not None:
                          pheno_covar.add_subject(indid, sex, pheno)
                      if len(words) > 0:
                          self.families.append(words)
                  else:
                      mask_components.append(1)
          mask_components = numpy.array(mask_components)
          self.ind_mask = numpy.zeros(len(mask_components), dtype=numpy.int8)
          self.ind_mask = mask_components
          self.ind_count = self.ind_mask.shape[0]
          if pheno_covar is not None:
              pheno_covar.freeze_subjects()
docs: Load contents from the .fam file, updating the pheno_covar with \
              family ids found.
  
          :param pheno_covar: Phenotype/covariate object
          :return: None