Let $f \in L^1 (\mathbb{R}), f_n(x):=f(x-\frac{1}{n})$. Prove that $f_n$ converges to $f$ in $L^1(\mathbb{R})$.

Question

I'm trying to solve some real analysis question, and I have no clue how to solve this one.

$$ \text{Let: }f \in L^1 (\mathbb{R}), f_n(x):=f(x-\frac{1}{n})$$ $$ \text{Prove that } f_n \text{ converges to } f \text{ in } L^1(\mathbb{R}) \text{ when } n\rightarrow\infty $$

Do you have any ideas? Thanks!