Product of Injective Spaces is Injective

Theorem
Let $I$ be a non-empty indexing set.

Let $\family {\struct {S_i, \tau_i} }_{i \mathop \in I}$ be an indexed family of injective topological spaces.

Then $\ds \prod_{i \mathop \in I} \struct {S_i, \tau_i}$ is injective space.