class_docstr: A helper class that represents input list values that to be modified.
  
  Operations which modify field_value would generate new Field instance.
docstr: Insert items before index.
  
  :param int|list|slice index:
      can be int indicate insert single item or their list like [1, 2, 3]
      can be list like (0,3) indicate replace items from 0
          to 3(not included) or their list like [(0, 3), (5,6)]
      can be slice which would be convert to list.
  :param list new_items: items corresponding index.
  :return: new field object.
docstr_tok: ["Insert","items","before","index",".",":","param","int|list|slice","index",":","can","be","int","indicate","insert","single","item","or","their","list","like","[","1",",","2",",","3","]","can","be","list","like","(","0,3",")","indicate","replace","items","from","0","to","3","(","not","included",")","or","their","list","like","[","(","0",",","3",")",",","(","5,6",")","]","can","be","slice","which","would","be","convert","to","list",".",":","param","list","new_items",":","items","corresponding","index",".",":","return",":","new","field","object","."]
code: def insert_before_index(self, index, new_items):
      r"""
      Insert items before index.
  
      :param int|list|slice index:
          can be int indicate insert single item or their list like [1, 2, 3]
          can be list like (0,3) indicate replace items from 0
              to 3(not included) or their list like [(0, 3), (5,6)]
          can be slice which would be convert to list.
      :param list new_items: items corresponding index.
      :return: new field object.
  
      """
      return self.insert_before_indices([index], [new_items])
  
file_path: textflint/textflint/input/component/field/list_field.py
imports: from .field import Field
  from ....common.utils.list_op import *
label_desc: Use image node_id 7 for calling the ListField obj's underlying member method code with example usage: obj.insert_before_index(index, new_items) and returns: self