code: def _add_editor_buffer(self, editor_buffer, show_in_current_window=False):
          
          assert isinstance(editor_buffer, EditorBuffer) and editor_buffer not in self.editor_buffers
  
          # Add to list of EditorBuffers
          eb = self.active_editor_buffer
          if eb is None:
              self.editor_buffers.append(editor_buffer)
          else:
              # Append right after the currently active one.
              try:
                  index = self.editor_buffers.index(self.active_editor_buffer)
              except ValueError:
                  index = 0
              self.editor_buffers.insert(index, editor_buffer)
  
          # When there are no tabs/windows yet, create one for this buffer.
          if self.tab_pages == []:
              self.tab_pages.append(TabPage(Window(editor_buffer)))
              self.active_tab_index = 0
  
          # To be shown?
          if show_in_current_window and self.active_tab:
              self.active_tab.show_editor_buffer(editor_buffer)
  
          # Start reporter.
          editor_buffer.run_reporter()
docs: Insert this new buffer in the list of buffers, right after the active
          one.