Flow - Knex typing

flow-knex.jsx

// Flow definition
declare module 'knex' {
  declare class SchemaBuilder {
    ...
    createTable(name:string, fn:() => void): this;
  }
  
  declare class TableBuilder {
    ...
  }
} 

// Now calling the code like this:

knex.schema.createTable('users', function() {
  /**
   * Here flow should identify `this` as `TableBuilder`
   */
  this.column('id').primary();
  this.column('username');
});

/*
 Here I can do `(this:TableBuilder)`, but I would like to know if there is a more elegant way :)
 */