Partial Type

src/libraries/System.Private.CoreLib/src/System/Buffers/Text/Base64Helper/Base64DecoderHelper.cs

src/libraries/System.Private.CoreLib/src/System/Buffers/Text/Base64Helper/Base64EncoderHelper.cs

src/libraries/System.Private.CoreLib/src/System/Buffers/Text/Base64Helper/Base64Helper.cs

src/libraries/System.Private.CoreLib/src/System/Buffers/Text/Base64Helper/Base64ValidatorHelper.cs