docs: def get_case(family_lines, family_type='ped', vcf_path=None):
      """Return ped_parser case from a family file
      
      Create a dictionary with case data. If no family file is given create from VCF
      
      Args:
          family_lines (iterator): The family lines
          family_type (str): The format of the family lines
          vcf_path(str): Path to VCF
      
      Returns:
          family (Family): A ped_parser family object
      """
      family = None
      LOG.info("Parsing family information")
      
      family_parser = FamilyParser(family_lines, family_type)
      
      families = list(family_parser.families.keys())
      
      LOG.info("Found families {0}".format(', '.join(families)))
      
      if len(families) > 1:
          raise CaseError("Only one family per load can be used")
      
      family = family_parser.families[families[0]]
      
      return family