public static String toBits(final long x){
  final StringBuilder sb=new StringBuilder();
  long t=x;
  for (int i=0; i < 64; i++) {
    if ((i & 7) == 0 && i > 0) {
      sb.append(":");
    }
    sb.append(t < 0 ? "1" : "0");
    t=t << 1;
  }
  assert t == 0;
  return sb.toString();
}

public static String toBits ( final long x ) { final StringBuilder sb = new StringBuilder ( ) ; long t = x ; for ( int i = 0 ; i < 64 ; i ++ ) { if ( ( i & 7 ) == 0 && i > 0 ) { sb . append ( ":" ) ; } sb . append ( t < 0 ? "1" : "0" ) ; t = t << 1 ; } assert t == 0 ; return sb . toString ( ) ; }
convert a number into a bit string with separators between each group of 8 .
