public LocalVariable visibleVariableByName(String name) throws AbsentInformationException {
  validateStackFrame();
  createVisibleVariables();
  return visibleVariables.get(name);
}

public LocalVariable visibleVariableByName ( String name ) throws AbsentInformationException { validateStackFrame ( ) ; createVisibleVariables ( ) ; return visibleVariables . get ( name ) ; }
return a particular variable in the frame . need not be synchronized since it cannot be provably stale .
