isNonNegative top-level constant

const isNonNegative = const _OrderingMatcher(0, true, false, true, 'a non-negative value', false)

A matcher which matches if the match argument is zero or positive.

Implementation 

const Matcher isNonNegative =
    const _OrderingMatcher(0, true, false, true, 'a non-negative value', false)