Representations for HTTP message entities.
An entity is the optional content of a
message.
You'll find a basic selection of entity implementations here.
If you need to send an entity, you can provide it for example as a
byte array,
string,
file, or through an arbitrary
input stream.
If you receive a message with an entity, you typically get that as a
basic entity.
Entity implementations can be
wrapped,
for example to
buffer
the content in memory.
