void collectUnresolvedYetArgumentsTo(Set<String> unresolvedYetArguments) {
    this.unresolvedYetArguments = unresolvedYetArguments;
  }
Encapsulates routines and various hacks for get relevant strings for the raw types and type
parameters, while attempting to resolve unresolved types using source imports.
value-processor/src/org/immutables/value/processor/meta/TypeStringProvider.java