add missing Guard.NotNull checks

src/ImageSharp/MetaData/Profiles/ICC/IccDataReader.cs

@@ -37,6 +37,7 @@ namespace ImageSharp
         /// <param name="data">The data to read</param>
         public IccDataReader(byte[] data)
         {
+            Guard.NotNull(data, nameof(data));
             this.data = data;
         }
 

src/ImageSharp/MetaData/Profiles/ICC/IccReader.cs

@@ -17,6 +17,7 @@ namespace ImageSharp
         /// <returns>The read ICC profile</returns>
         public IccProfile Read(byte[] data)
         {
+            Guard.NotNull(data, nameof(data));
             Guard.IsTrue(data.Length >= 128, nameof(data), "Data length must be at least 128 to be a valid ICC profile");
 
             IccDataReader reader = new IccDataReader(data);
@@ -33,6 +34,7 @@ namespace ImageSharp
         /// <returns>The read ICC profile header</returns>
         public IccProfileHeader ReadHeader(byte[] data)
         {
+            Guard.NotNull(data, nameof(data));
             Guard.IsTrue(data.Length >= 128, nameof(data), "Data length must be at least 128 to be a valid profile header");
 
             IccDataReader reader = new IccDataReader(data);
@@ -46,6 +48,7 @@ namespace ImageSharp
         /// <returns>The read ICC profile tag data</returns>
         public IccTagDataEntry[] ReadTagData(byte[] data)
         {
+            Guard.NotNull(data, nameof(data));
             Guard.IsTrue(data.Length >= 128, nameof(data), "Data length must be at least 128 to be a valid ICC profile");
 
             IccDataReader reader = new IccDataReader(data);

src/ImageSharp/MetaData/Profiles/ICC/IccWriter.cs

@@ -20,6 +20,8 @@ namespace ImageSharp
         /// <returns>The ICC profile as a byte array</returns>
         public byte[] Write(IccProfile profile)
         {
+            Guard.NotNull(profile, nameof(profile));
+
             IccDataWriter writer = new IccDataWriter();
             IccTagTableEntry[] tagTable = this.WriteTagData(writer, profile.Entries);
             this.WriteTagTable(writer, tagTable);