Suppose $f$ is a continuous map from a space $A$ to a Hausdorff space Y. Then I know that $f$ can be extended uniquely to a continuous map from closure of $A$ to Y. What is a counterexample to the fact that this need not be true if Y is not Hausdorff? I think two point sets will work (and this has been hinted here [Uniqueness of continuous extension from $A$ to $\overline{A}$ for maps into a Hausdorff space](https://math.stackexchange.com/questions/904600/uniqueness-of-continuous-extension-from-a-to-overlinea-for-maps-into-a-ha)), but how?