Tezos_lazy_containers.Lazy_vectorSourceA lazy vector is a fixed-size key-value association where each value is created dynamically.
In many ways this data structure mimics an array, but its lookup has logarithmic time complexity and it supports non-int keys.
KeyS is the qualifier signature for key types in the lazy vector. Externally visible and accessible keys of the lazy vector are always non-negative. However, the lazy vector implementation may internally use negative keys therefore modules of type KeyS must support them.