//! Canonical imported polygon payload.
//!
//! Vector and line readers normalize their format-specific geometry into rings
//! of `[x, y, z]`; `core` then turns those rings into the domain-facing
//! `PolygonSet`.
/// Imported polygon rings. Each ring is an ordered vertex list; Z is retained
/// at import time and intentionally dropped by the areal `PolygonSet` domain
/// object.
pub