code: public Json jsonSchema(String jsonSchema) {
  		Preconditions.checkNotNull(jsonSchema);
  		this.jsonSchema = jsonSchema;
  		this.schema = null;
  		this.deriveSchema = null;
  		return this;
  	}
docs: Sets the JSON schema string with field names and the types according to the JSON schema
  specification [[http://json-schema.org/specification.html]].
  
  <p>The schema might be nested.
  
  @param jsonSchema JSON schema