code: protected boolean isLegalEmphOrStrongClosePos(){
          Object lastItem = peek();
          if ( StrongEmphSuperNode.class.equals( lastItem.getClass() ) ){
              List<Node> children = ((StrongEmphSuperNode) lastItem).getChildren();
          
              if(children.size() < 1)
                  return true;
  
              lastItem = children.get( children.size()-1 );
              Class<?> lastClass = lastItem.getClass();
              
              if( TextNode.class.equals(lastClass) )
                  return !((TextNode) lastItem).getText().endsWith(" ");
  
              if( SimpleNode.class.equals(lastClass) )
                  return !((SimpleNode) lastItem).getType().equals(SimpleNode.Type.Linebreak);
              
          }
          return true;
      }
docs: This method checks if the last parsed character or sequence is a valid prefix for a closing char for
  an emph or strong sequence.