UnboundEpsilonSummary with epsilon=0.01 always panic when size exceeds 6553499

[ZiJiaW]

let mut q = UnboundEpsilonSummary::new(0.01);
for i in 0..7000000 {
    q.update(i)
}

Panic happens and the size always stops at 6553499. When I change epsilon to 0.001, it disappered.

PanicException: index out of bounds: the len is 32 but the index is 32