Show integral equality?

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How to get this equality ? $$ \forall z\in\mathbb C\backslash\mathbb R_- \;,\ \mathrm{Re}\left\{\int_0^1 \dfrac{z-1}{x(z-1)+1} \,\mathrm dx\right\} = \int_0^1 \dfrac{\vert z\vert -1}{x(\vert z\vert -1) +1}\,\mathrm dx $$ I tried to expand with real and imaginary parts but without success...