public boolean isBeginningInstruction(){
  if (predecessors.size() == 0) {
    return false;
  }
  return predecessors.first().instructionIndex == -1;
}

public boolean isBeginningInstruction ( ) { if ( predecessors . size ( ) == 0 ) { return false ; } return predecessors . first ( ) . instructionIndex == - 1 ; }
is this instruction a " beginning instruction " . a beginning instruction is defined to be an instruction that can be the first successfully executed instruction in the method . the first instruction is always a beginning instruction . if the first instruction can throw an exception , and is covered by a try block , then the first instruction of any exception handler for that try block is also a beginning instruction . and likewise , if any of those instructions can throw an exception and are covered by try blocks , the first instruction of the corresponding exception handler is a beginning instruction , etc . < p / > to determine this , we simply check if the first predecessor is the fake " startofmethod " instruction , which has an instruction index of - 1 .
