code: public DocumentLoader addInjectedDoc(String url, String doc) throws JsonLdError {
          try {
              m_injectedDocs.put(url, JsonUtils.fromString(doc));
              return this;
          } catch (final Exception e) {
              throw new JsonLdError(JsonLdError.Error.LOADING_INJECTED_CONTEXT_FAILED, url, e);
          }
      }
docs: Avoid resolving a document by instead using the given serialised
  representation.
  
  @param url
  The URL this document represents.
  @param doc
  The serialised document as a String
  @return This object for fluent addition of other injected documents.
  @throws JsonLdError
  If loading of the document failed for any reason.