Tests for Geometry.union() method (unary union) P - point (showing merging of identical points) MULTIPOINT((10 10), (0 0), (10 10)) MULTIPOINT((10 10), (0 0)) P - point (showing merging of identical points) MULTIPOINT((10 10), (0 0), (10 10), (10 10), (10 10), (5 5), (5 5)) MULTIPOINT((10 10), (5 5), (0 0)) L - LineString (showing noding) LINESTRING (0 0, 10 0, 5 -5, 5 5) MULTILINESTRING ((0 0, 5 0), (5 0, 10 0, 5 -5, 5 0), (5 0, 5 5)) mL - multiLineString (showing noding) MULTILINESTRING((0 0, 10 10), (0 10, 10 0)) MULTILINESTRING ((0 0, 5 5), (5 5, 10 10), (0 10, 5 5), (5 5, 10 0)) GC - shows handling linear rings and linestrings GEOMETRYCOLLECTION (LINEARRING (0 0, 0 70, 80 70, 80 0, 0 0), LINESTRING (30 110, 30 30, 100 30)) MULTILINESTRING ((0 0, 0 70, 30 70), (30 70, 80 70, 80 30), (80 30, 80 0, 0 0), (30 110, 30 70), (30 70, 30 30, 80 30), (80 30, 100 30)) mL - multiLineString (showing noding and dissolving) MULTILINESTRING((0 0, 10 10), (5 5, 15 15)) MULTILINESTRING ((0 0, 5 5), (5 5, 10 10), (10 10, 15 15)) mP - multiPolygon (invalid) MULTIPOLYGON (((0 0, 0 100, 100 100, 100 0, 0 0)), ((70 160, 70 70, 160 70, 160 160, 70 160))) POLYGON ((0 0, 0 100, 70 100, 70 160, 160 160, 160 70, 100 70, 100 0, 0 0)) GC - geometry collection (homo) GEOMETRYCOLLECTION (POLYGON ((0 0, 0 100, 100 100, 100 0, 0 0)), POLYGON ((70 160, 70 70, 160 70, 160 160, 70 160))) POLYGON ((0 0, 0 100, 70 100, 70 160, 160 160, 160 70, 100 70, 100 0, 0 0)) GC - geometry collection (hetero LA) GEOMETRYCOLLECTION (POLYGON ((0 0, 0 100, 100 100, 100 0, 0 0)), POLYGON ((70 160, 70 70, 160 70, 160 160, 70 160)), LINESTRING (40 70, 40 160)) GEOMETRYCOLLECTION (LINESTRING (40 100, 40 160), POLYGON ((0 0, 0 100, 40 100, 70 100, 70 160, 160 160, 160 70, 100 70, 100 0, 0 0))) GC - geometry collection (hetero PL) GEOMETRYCOLLECTION (LINESTRING (40 60, 120 110), POINT (120 110), POINT (40 60)) LINESTRING (40 60, 120 110) GC - geometry collection (hetero PL) GEOMETRYCOLLECTION (LINESTRING (40 60, 120 110), POINT (120 110), POINT (40 60), POINT (100 70), POINT (80 50)) GEOMETRYCOLLECTION (POINT (80 50), POINT (100 70), LINESTRING (40 60, 120 110)) mP - multipolygon (invalid) with topology collapse MULTIPOLYGON (((0 0, 150 0, 150 1, 0 0)), ((180 0, 20 0, 20 100, 180 100, 180 0))) POLYGON ((150 0, 20 0, 20 100, 180 100, 180 0, 150 0))