I am attempting to intentionally add noise to my qiskit circuit by applying n-pairs of CNOT gates. The effect of this should be to yield the same result of my baseline (no pairs of CNOT gates applied) circuit with the addition of some noise. However, the result of my "noisy" circuit looks the same as my baseline even for large n. My best guess is that qiskit automatically removes unnecessary operations (like a pair of CNOTs) in an effort to reduce the number of gates. If this is true, then how can I add a series of gates which will keep the baseline circuit the same but will add gate noise?