* one of the listener's callbacks will execute at once. However, multiple listeners' callbacks
   * may execute concurrently, and listeners may execute in an order different from the one in which
   * they were registered.
   *
   * <p>RuntimeExceptions thrown by a listener will be caught and logged. Any exception thrown
   * during {@code Executor.execute} (e.g., a {@code RejectedExecutionException}) will be caught and

#
#   JAVA_HOME           (Optional) Points to a Java installation.
#   MAVEN_ARGS          (Optional) Arguments passed to Maven before CLI arguments.
#   MAVEN_OPTS          (Optional) Java runtime options used when Maven is executed.
#   MAVEN_SKIP_RC       (Optional) Flag to disable loading of mavenrc files.

  // Block until all pending nodes are finished.
  virtual absl::Status AsyncWait() = 0;

  // Add a function (serialized FunctionDef protocol buffer) so that it can
  // be executed as an op. Return error if the function with the same name
  // already exists.
  virtual absl::Status AddFunctionDef(const FunctionDef& fdef) = 0;

  // Notifies about the function removal.

If the effect of an atomic operation <i>A</i> is observed by atomic operation <i>B</i>,
then <i>A</i> is synchronized before <i>B</i>.
All the atomic operations executed in a program behave as though executed
in some sequentially consistent order.
</p>

<p>
The preceding definition has the same semantics as C++’s sequentially consistent atomics
and Java’s <code>volatile</code> variables.
</p>

    }
  }

  public void testVerifyGetsCalled() {
    TesterThatCountsCalls tester = new TesterThatCountsCalls();

    tester.test();

    assertEquals(
        "Should have verified once per stimulus executed",
        tester.numCallsToVerify,
        tester.numCallsToNewTargetIterator * STEPS);
  }

  public void testVerifyCanThrowAssertionThatFailsTest() {

@REM   MAVEN_BATCH_PAUSE (Optional) set to 'on' to wait for a key stroke before ending.
@REM   MAVEN_OPTS        (Optional) Java runtime options used when Maven is executed.
@REM   MAVEN_SKIP_RC     (Optional) Flag to disable loading of mavenrc files.
@REM -----------------------------------------------------------------------------

// Test to ensure that a registered graph optimization pass is only executed
// once (i.e., on the main function side) in running distributed functions.
// This test creates a cluster with two workers, create a variable on the
// second worker, and run a distributed function (VariableAddFunction) whose ops
// span the local and remote workers. If the graph optimization pass is executed

# Output control
#-----------------------------------------------------------------------------
# Invoke make VERBOSE=1 to enable echoing of the command being executed
export VERBOSE ?= 0
# Place the variable Q in front of a command to control echoing of the command being executed.
Q = $(if $(filter 1,$VERBOSE),,@)
# Use the variable H to add a header (equivalent to =>) to informational output
H = $(shell printf "\033[34;1m=>\033[0m")

You don't even have to check if the token exists to return an error. You can be sure that if your function is executed, it will have a `str` in that token.

You can try it already in the interactive docs:

<img src="/img/tutorial/security/image03.png">

We are not verifying the validity of the token yet, but that's a start already.

      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,