anchor.diff:  
   === Customising the data to be imported via configuration file
   
  -It is also possible configure what data will be imported to Neo4j through a configuration file. By passing a JSON such as link:https://github.com/mongodb-labs/mongo-connector/blob/master/config.json[this example] during __mongo-connetor__ startup you can set which namespaces will be included. For example, consider the following file, called **config.json**:
  +It is also possible to configure what data will be imported to Neo4j through a configuration file. By passing a JSON file such as link:https://github.com/mongodb-labs/mongo-connector/blob/master/config.json[this example] during __mongo-connetor__ startup you can set which namespaces will be included. For example, consider the following file, called **config.json**:
   
   [source, javascript]
   ----
  
positive.code: }
  ----
  
  The same principles that were described into the previous session through command line configuration are applied via configuration file. The key __field__ holds a string array of fields that will be imported.
  
  Just a remainder, you can only specify the fields of the root document and the direct nested documents that will be imported. 
  
  
  === Errors and exceptions
  
negative.code: 
  ===== Authentication
  
  If you have authentication enabled for Neo4j, be sure to set **NEO4J_AUTH** environment variable, containing your username and password.
  
  ```
  export NEO4J_AUTH=<user>:<password>
  