- **I/O Operations** (`org.codelibs.core.io`) - File handling, resource management, stream utilities, and traversal utilities for efficient resource processing
- **Reflection** (`org.codelibs.core.lang`) - Class loading, method/field access, type introspection utilities, and generics support

    TypeVariableImpl<D> typeVariableImpl = new TypeVariableImpl<>(genericDeclaration, name, bounds);
    @SuppressWarnings("unchecked")
    TypeVariable<D> typeVariable =
        Reflection.newProxy(
            TypeVariable.class, new TypeVariableInvocationHandler(typeVariableImpl));
    return typeVariable;
  }

  /**

        // We can't directly test ProcessDestroyer without creating actual processes,
        // but we can test that the class exists and basic functionality
        try {
            // Use reflection to verify ProcessDestroyer class exists
            final Class<?> destroyerClass = Class.forName("org.codelibs.fess.thumbnail.impl.CommandGenerator$ProcessDestroyer");

    /*
     * We'd use assertThrows here, but that causes no exception to be thrown under Java 8,
     * presumably because the ThrowingRunnable lambda triggers some kind of bug in Java 8's
     * reflection implementation.
     */
    try {
      new TypeToken<T>() {};
      fail();
    } catch (IllegalStateException expected) {
      // Type variables aren't allowed.
    }
  }

    /*
     * We'd use assertThrows here, but that causes no exception to be thrown under Java 8,
     * presumably because the ThrowingRunnable lambda triggers some kind of bug in Java 8's
     * reflection implementation.
     */
    try {
      new TypeToken<T>() {};
      fail();
    } catch (IllegalStateException expected) {
      // Type variables aren't allowed.
    }
  }

    TypeVariableImpl<D> typeVariableImpl = new TypeVariableImpl<>(genericDeclaration, name, bounds);
    @SuppressWarnings("unchecked")
    TypeVariable<D> typeVariable =
        Reflection.newProxy(
            TypeVariable.class, new TypeVariableInvocationHandler(typeVariableImpl));
    return typeVariable;
  }

  /**

    <j2objc.version>3.1</j2objc.version>
    <project.build.outputTimestamp>2025-01-02T00:00:00Z</project.build.outputTimestamp>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <!--
    Some tests need reflective access to the internals of these packages. It is only the
    tests themselves and not the code being tested that needs that access, though there's no
    obvious way to ensure that.

    <j2objc.version>3.1</j2objc.version>
    <project.build.outputTimestamp>2025-01-02T00:00:00Z</project.build.outputTimestamp>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <!--
    Some tests need reflective access to the internals of these packages. It is only the
    tests themselves and not the code being tested that needs that access, though there's no
    obvious way to ensure that.