code: function expandImplicitContent( attribs ) {
      try {
          if ( !attribs ) return;
          if ( typeof attribs.implicit === 'undefined' ) return;
          const implicitContent = attribs.implicit[ 1 ];
          if ( typeof implicitContent === 'undefined' ) return;
  
          const explicitContent = attribs.standard ? attribs.standard.content : undefined;
          if ( explicitContent ) {
              throw "Can't mix implicit and explicit `content`:\n" +
                  "    implicit: " + limitJson( implicitContent ) + "\n" +
                  "    explicit: " + limitJson( explicitContent );
          }
  
          attribs.standard.content = implicitContent;
      } catch ( ex ) {
          throw ex + "\n...in expandImplicitContent: " + limitJson( attribs );
      }
  }
docs: The following syntaxes are equivalent:
  @example
  // Explicit content
  {tfw.view.expand content: Hello}
  // Implicit content
  {tfw.view.expand Hello}