Sampling sequences similar to a given sequence
# 🚀 Feature request

Sampling sequences similar to the previously generated sequence. 

Example: 

A language model produces the following "I went for a walk with my dog". During the next step we request a model to produce a similar sequence. It produces: "He went for a walk with his cat".

## Motivation

Very useful for downstream applications.

## Your contribution

Can review PR and help with implementation.

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