code: public boolean validate() {
  
          if (m_end >= m_length) {
              m_end = m_length - 1;
          }
  
          return ((m_start >= 0) && (m_end >= 0) && (m_start <= m_end) && (m_length > 0));
      }
docs: Validate range.<p>
  
  @return true if the actual range is valid otherwise false