public final Class Any

`Any` contains an arbitrary serialized protocol buffer message along with a
URL that describes the type of the serialized message.
Protobuf library provides support to pack/unpack Any values in the form
of utility functions or additional generated methods of the Any type.
Example 1: Pack and unpack a message in C++.
    Foo foo = ...;
    Any any;
    any.PackFrom(foo);
    ...
    if (any.UnpackTo(&foo)) {
      ...
    }
Example 2: Pack and unpack a message in Java.
    Foo foo = ...;
    Any any = Any.pack(foo);
    ...
    if (any.is(Foo.class)) {
      foo = any.unpack(Foo.class);
    }
 Example 3: Pack and unpack a message in Python.
    foo = Foo(...)
    any = Any()
    any.Pack(foo)
    ...
    if any.Is(Foo.DESCRIPTOR):
      any.Unpack(foo)
      ...
 Example 4: Pack and unpack a message in Go
     foo := &pb.Foo{...}
     any, err := ptypes.MarshalAny(foo)
     ...
     foo := &pb.Foo{}
     if err := ptypes.UnmarshalAny(any, foo); err != nil {
       ...
     }
The pack methods provided by protobuf library will by default use
'type.googleapis.com/full.type.name' as the type URL and the unpack
methods only use the fully qualified type name after the last '/'
in the type URL, for example "foo.bar.com/x/y.z" will yield type
name "y.z".
JSON
====
The JSON representation of an `Any` value uses the regular
representation of the deserialized, embedded message, with an
additional field `@type` which contains the type URL. Example:
    package google.profile;
    message Person {
      string first_name = 1;
      string last_name = 2;
    }
    {
      "@type": "type.googleapis.com/google.profile.Person",
      "firstName": <string>,
      "lastName": <string>
    }
If the embedded message type is well-known and has a custom JSON
representation, that representation will be embedded adding a field
`value` which holds the custom JSON in addition to the `@type`
field. Example (for message [google.protobuf.Duration][]):
    {
      "@type": "type.googleapis.com/google.protobuf.Duration",
      "value": "1.212s"
    }