Estimate single-qubit readout error.

For each qubit, prepare the |0⟩ state and measure. Calculate how often a 1 is measured. Also, prepare the |1⟩ state and calculate how often a 0 is measured. The state preparations and measurements are done in parallel, i.e., for the first experiment, we actually prepare every qubit in the |0⟩ state and measure them simultaneously.

sampler The quantum engine or simulator to run the circuits.
qubits The qubits being tested.
repetitions The number of measurement repetitions to perform.

A SingleQubitReadoutCalibrationResult storing the readout error probabilities as well as the number of repetitions used to estimate the probabilities. Also stores a timestamp indicating the time when data was finished being collected from the sampler.