nboot: numeric value specifying
number of samples alpha: numeric value
specifying complement of confidence interval
seed: vector of integers specifying seed
for pseudo-random number generator used
compare: vector of character strings
naming groups compared rng: character
string naming type of random number generator
stat: matrix matrix with columns
observed, median, lower, upper for estimates
what: character vector naming what was
resampled: clusters, units, both
excludedClusters: character vector naming
clusters excluded because of missing treatment(s)
call: the call to MFClusBoot
sample: what is this? mf-classMFClusBoot Other mf: mf-class,
mfboot-class, mfhlboot-class