guava/src/com/google/common/net/MediaType.java
public MediaType withParameters(Multimap<String, String> parameters) {
    return create(type, subtype, parameters);
  }
public MediaType withParameters(Multimap<String, String> parameters) {
    return create(type, subtype, parameters);
  }
<em>Replaces</em> all parameters with the given parameters.

@throws IllegalArgumentException if any parameter or value is invalid