code: public ClientExtension setRequestableScopes(Set<String> scopes)
      {
          if (scopes == null)
          {
              this.requestableScopes = null;
  
              return this;
          }
  
          int size = scopes.size();
  
          this.requestableScopes = new String[size];
  
          if (size != 0)
          {
              scopes.toArray(this.requestableScopes);
          }
  
          return this;
      }
docs: Set the set of scopes that this client application can request when
  <i>"Requestable Scopes per Client"</i> is enabled (= when {@link
  #isRequestableScopesEnabled()} returns {@code true}).
  
  <p>
  See the description of {@link #isRequestableScopesEnabled()} for details
  about <i>"Requestable Scopes per Client"</i>.
  </p>
  
  @param scopes
  A set of scopes.
  
  @return
  {@code this} object.
  
  @since 1.41