https://github.com/FasterXML/jackson-core: Core Jackson processing abstractions (aka Streaming API), implementation for JSON (FasterXML)
  • Tatu Saloranta
  • Christopher Currie
  • Paul Brown 
package com.fasterxml.jackson.core.util;


Add-on interface used to indicate things that may be "blueprint" objects which can not be used as is, but are used for creating usable per-process (serialization, deserialization) instances, using createInstance method. 
 Note that some implementations may choose to implement createInstance by simply returning 'this': this is acceptable if instances are stateless. 
See Also:
Since:2.1
/**
 * Add-on interface used to indicate things that may be "blueprint" objects
 * which can not be used as is, but are used for creating usable per-process
 * (serialization, deserialization) instances, using
 * {@link #createInstance} method.
 *<p>
 * Note that some implementations may choose to implement {@link #createInstance}
 * by simply returning 'this': this is acceptable if instances are stateless.
 * 
 * @see DefaultPrettyPrinter
 * 
 * @since 2.1
 */
public interface Instantiatable<T>
{
    
Method called to ensure that we have a non-blueprint object to use;
it is either this object (if stateless), or a newly created object
with separate state.

/**
     * Method called to ensure that we have a non-blueprint object to use;
     * it is either this object (if stateless), or a newly created object
     * with separate state.
     */
    T createInstance();
}