use unicode_segmentation::{GraphemeCursor,GraphemeIncomplete};#[test]fntest_graphemes_chunked(){useGraphemeIncomplete::*;let chunk0 ="👩";// 4 byteslet chunk1 ="\u{200d}🔬";// 3 bytes + 4 byteslet full =&(chunk0.to_string() + chunk1);// 👩‍🔬letmut cur =GraphemeCursor::new(0, full.len(),true);assert_eq!(cur.next_boundary(chunk0,0),Err(NextChunk));match cur.next_boundary(chunk1, chunk0.len()){Ok(res) =>assert_eq!(res,Some(11)),Err(PreContext(_)) =>{            cur.provide_context(chunk0,0);assert_eq!(cur.next_boundary(chunk1, chunk0.len()),Ok(Some(11)));}        _ =>unreachable!(),}}