code: def _input_stmt(self, stmt: object) -> tuple:
          
          code = ''
          cls = ''
          if isinstance(stmt, str):
              code += "%s " % (stmt)
          elif isinstance(stmt, dict):
              try:
                  if 'interval' in stmt.keys():
                      if isinstance(stmt['interval'], str):
                          code += "%s " % stmt['interval']
                      if isinstance(stmt['interval'], list):
                          code += "%s " % " ".join(stmt['interval'])
                  if 'nominal' in stmt.keys():
                      if isinstance(stmt['nominal'], str):
                          code += "%s " % stmt['nominal']
                          cls += "%s " % stmt['nominal']
                      if isinstance(stmt['nominal'], list):
                          code += "%s " % " ".join(stmt['nominal'])
                          cls += "%s " % " ".join(stmt['nominal'])
              except:
                  raise SyntaxError("Proper Keys not found for INPUT dictionary: %s" % stmt.keys())
          elif isinstance(stmt, list):
              if len(stmt) == 1:
                  code += "%s" % str(stmt[0])
              elif len(stmt) > 1:
                  code += "%s" % " ".join(stmt)
              else:
                  raise SyntaxError("The input list has no members")
          else:
              raise SyntaxError("INPUT is in an unknown format: %s" % str(stmt))
          return (code, cls)
docs: takes the input key from kwargs and processes it to aid in the generation of a model statement
          :param stmt: str, list, or dict that contains the model information.
          :return: tuple of strings one for the class statement one for the model statements