Base:
method
AddSynthesizedReturnTypeAttributes
Microsoft.CodeAnalysis.CSharp.Symbols.MethodSymbol.AddSynthesizedReturnTypeAttributes(Microsoft.CodeAnalysis.CSharp.Emit.PEModuleBuilder, ref Microsoft.CodeAnalysis.PooledObjects.ArrayBuilder<Microsoft.CodeAnalysis.CSharp.Symbols.SynthesizedAttributeData>)