feat: parse subscription close requests from websockets

src/close.rs

@@ -0,0 +1,22 @@
+use crate::error::{Error, Result};
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize, PartialEq, Debug, Clone)]
+pub struct Close {
+    cmd: String,
+    id: String,
+}
+
+impl Close {
+    pub fn parse(json: &str) -> Result<Close> {
+        let c: Close = serde_json::from_str(json)?; //.map_err(|e| Error::JsonParseFailed(e));
+        if c.cmd != "CLOSE" {
+            return Err(Error::CloseParseFailed);
+        }
+        return Ok(c);
+    }
+
+    pub fn get_id(&self) -> String {
+        self.id.clone()
+    }
+}