code: public BuildWithDetails updateDisplayName(String displayName, boolean crumbFlag) throws IOException {
          Objects.requireNonNull(displayName, "displayName is not allowed to be null.");
          String description = getDescription() == null ? "" : getDescription();
          Map<String, String> params = new HashMap<>();
          params.put("displayName", displayName);
          params.put("description", description);
          // TODO: Check what the "core:apply" means?
          params.put("core:apply", "");
          params.put("Submit", "Save");
          client.post_form(this.getUrl() + "/configSubmit?", params, crumbFlag);
          return this;
      }
docs: Update <code>displayName</code> of a build.
  
  @param displayName The new displayName which should be set.
  @param crumbFlag <code>true</code> or <code>false</code>.
  @throws IOException in case of errors.