code: def _create_field_mapping_action(self):
          
          icon = resources_path('img', 'icons', 'show-mapping-tool.svg')
          self.action_field_mapping = QAction(
              QIcon(icon),
              self.tr('InaSAFE Field Mapping Tool'),
              self.iface.mainWindow())
          self.action_field_mapping.setStatusTip(self.tr(
              'Assign field mapping to layer.'))
          self.action_field_mapping.setWhatsThis(self.tr(
              'Use this tool to assign field mapping in layer.'))
          self.action_field_mapping.setEnabled(False)
          self.action_field_mapping.triggered.connect(self.show_field_mapping)
          self.add_action(
              self.action_field_mapping, add_to_toolbar=self.full_toolbar)
docs: Create action for showing field mapping dialog.