@Override
	public boolean getAllPossibleValues(List<Completion> completions, Class<?> targetType, String existingData,
			String optionContext, MethodTarget target) {
		return false;
	}
Knows how to parse String representations of {@link MediaType}.

@author Eric Bottard
spring-xd-shell/src/main/java/org/springframework/xd/shell/converter/MediaTypeConverter.java