An extension of {@link ContentProvider} that provides a content type string to be used as a {@code Content-Type} HTTP header in requests.
@return the content type string such as "application/octet-stream" or "application/json;charset=UTF8", or null if no content type must be set
@return the content length, if known, or -1 if the content length is unknown
See Implementation
An extension of {@link ContentProvider} that provides a content type string to be used as a {@code Content-Type} HTTP header in requests.