Add extension stream method

NvimView/NvimView/NvimApiExtension.swift

@@ -5,6 +5,7 @@
 
 import Foundation
 import NvimMsgPack
+import RxSwift
 
 extension NvimApi {
 
@@ -34,6 +35,28 @@ extension NvimApi {
   }
 }
 
+extension StreamApi {
+
+  public func getBufGetInfo(
+    buffer: NvimApi.Buffer
+  ) -> Single<Dictionary<String, NvimApi.Value>> {
+
+    let params: [NvimApi.Value] = [
+      .int(Int64(buffer.handle)),
+    ]
+
+    return self
+      .rpc(method: "nvim_buf_get_info", params: params, expectsReturnValue: true)
+      .map {
+        guard let result = (msgPackDictToSwift($0.dictionaryValue)) else {
+          throw NvimApi.Error.conversion(type: Dictionary<String, NvimApi.Value>.self)
+        }
+
+        return result
+      }
+  }
+}
+
 func msgPackDictToSwift(_ dict: Dictionary<NvimApi.Value, NvimApi.Value>?) -> Dictionary<String, NvimApi.Value>? {
   return dict?.flatMapToDict { k, v in
     guard let strKey = k.stringValue else {