Deserializes several values of type T by reading their textual representation from reader.
Deserializes several values of type T from a single textual representation string of all of them.
if string parses correctly as mimeType but does not encode a valid collection of T.
(a format-specific parsing exception, e.g. from the underlying Jackson ObjectMapper on the JVM) if string is not well-formed mimeType in the first place.