The name of the part.
The content of the part.
The optional content type.
The optional character encoding (defaults to UTF-8).
The optional content id.
The optional transfer encoding.
The optional character encoding (defaults to UTF-8).
The optional content id.
The optional content type.
The name of the part.
The optional transfer encoding.
The content of the part.
The name of the part.
The content of the part.
The optional content type.
The optional character encoding (defaults to UTF-8).
The optional content id.
The optional transfer encoding.