Can't collapse method with big method's header

void myMethod1(const std::vector >& matches1,
               const std::vector >& matches2,
                     std::vector& symMatches) { 
  // Some code of method
  // ...
  // some code
}

void myMethod1(const std::vector >& matches1, ...
  // Some code of method
  // ...
  // some code
}