public boolean hasChanged(){
  if (getValue() != null)   if (m_oldValue != null)   return !m_oldValue.equals(getValue());
 else   return true;
 else   if (m_oldValue != null)   return true;
 else   return false;
}

public boolean hasChanged ( ) { if ( getValue ( ) != null ) if ( m_oldValue != null ) return ! m_oldValue . equals ( getValue ( ) ) ; else return true ; else if ( m_oldValue != null ) return true ; else return false ; }
has the field changed over time ?
