def main(ctx):
    which = "where" if sys.platform == "win32" else "which"
    if envoy.run(which + " git").status_code != 0:
        click.secho("fatal: git not found in PATH", fg="red")
        sys.exit(1)
    ctx.obj = Hydrogen()
def f(i):
        start = W[i]
        extent = W[i + 1] - W[i]
        rv = te.reduce_axis((0, extent))
        return te.sum(X[rv + start], axis=rv)