docstr: for the moment, if the table *does* exist, we are not checking
  for the index.  this can possibly be changed.
docstr_tok: ["for","the","moment",",","if","the","table","*","does","*","exist",",","we","are","not","checking","for","the","index",".","this","can","possibly","be","changed","."]
code: def test_create_table_exists_index_checkfirst(self):
      """for the moment, if the table *does* exist, we are not checking
      for the index.  this can possibly be changed."""
  
      m, t1, i1 = self._table_index_fixture()
  
      def exists(name):
          if name == "my_idx":
              raise NotImplementedError()
          else:
              return True
  
      generator = self._mock_create_fixture(
          True, [t1], item_exists=exists
      )
      # nothing is created
      self._assert_create([], generator, t1)
  
imports: from unittest.mock import Mock
  from sqlalchemy import Column
  from sqlalchemy import ForeignKey
  from sqlalchemy import Index
  from sqlalchemy import Integer
  from sqlalchemy import MetaData
  from sqlalchemy import schema
  from sqlalchemy import Sequence
  from sqlalchemy import Table
  from sqlalchemy.sql.ddl import SchemaDropper
  from sqlalchemy.sql.ddl import SchemaGenerator
  from sqlalchemy.testing import fixtures
label_desc: Use image node_id 14 for calling the EmitDDLTest obj's underlying member method code with example usage: obj.test_create_table_exists_index_checkfirst() and returns: True