code: def _camel_case(cls, text, first_upper=False):
          
          result = ''
          need_upper = False
          for pos, symbol in enumerate(text):
              if symbol == '_' and pos > 0:
                  need_upper = True
              else:
                  if need_upper:
                      result += symbol.upper()
                  else:
                      result += symbol.lower()
                  need_upper = False
          if first_upper:
              result = result[0].upper() + result[1:]
          return result
docs: Transform text to camelCase or CamelCase
  
          :param text:
          :param first_upper: first symbol must be upper?
          :return: