pub fn get_generator_of_subgroup(log_2_size: u32) -> Self {
        Self::GENERATOR.repeated_double(31 - log_2_size)
    }
Returns the generator of the subgroup of order n = 2^log_2_size.
We are using that 2^k * g is a generator of the subgroup of order 2^{31 - k}.
crates/math/src/circle/point.rs