Replace new_zstd_compressed with a more flexible new_with_options

Cargo.toml

@@ -24,7 +24,6 @@ zip = { version = "0.6.3", default-features = false, optional = true }
 default = ["compressed_npz", "num-complex-0_4"]
 npz = ["zip"]
 compressed_npz = ["npz", "zip/deflate"]
-compressed_npz_zstd = ["npz", "zip/zstd"]
 
 [dev-dependencies]
 memmap2 = "0.2"

src/npz.rs

@@ -103,16 +103,15 @@ impl<W: Write + Seek> NpzWriter<W> {
         }
     }
 
-    // TODO: it makes sense to add support for bzip2 also
-    // this necessitates some more generic API, as having three functions is janky... =)
-
-    /// Creates a new `.npz` file with zstd compression. While it is not directly supported by numpy,
-    /// it still could be useful (also it is possible to monkey-patch numpy to support it).
-    #[cfg(feature = "compressed_npz_zstd")]
-    pub fn new_zstd_compressed(writer: W, level: Option<i32>) -> NpzWriter<W> {
+    /// Creates a new `.npz` file with the specified options.
+    ///
+    /// This allows you to use a custom compression method, such as [`CompressionMethod::Zstd`] or set other options.
+    ///
+    /// Make sure to enable the `zstd` feature of the `zip` crate to use [`CompressionMethod::Zstd`] or other relevant features.
+    pub fn new_with_options(writer: W, options: FileOptions) -> NpzWriter<W> {
         NpzWriter {
             zip: ZipWriter::new(writer),
-            options: FileOptions::default().compression_method(CompressionMethod::ZSTD).compression_level(level),
+            options,
         }
     }