code: private static Scope getRootScope() {
          if (root == null) {
              synchronized (Scope.class) {
                  root = new Scope(true);
                  root.create("pi").makeConstant(Math.PI);
                  root.create("euler").makeConstant(Math.E);
              }
          }
  
          return root;
      }
docs: /*
  Creates the internal root scope which contains eternal constants ;-)