protected override BlockSyntax GenerateApplyAsyncBody() => Block(
MethodHelpers.ThrowIfArgumentNull(MessageParameterName),
MethodHelpers.IfNull(IdentifierName(CacheFieldName), Block(
ExpressionStatement(AssignmentExpression(SyntaxKind.SimpleAssignmentExpression,
IdentifierName(CacheFieldName),
WellKnownTypes.System.Convert.ToBase64String(WellKnownTypes.System.Text.Encoding.GetBytes(
WellKnownTypes.System.Text.Encoding.UTF8,
BinaryExpression(SyntaxKind.AddExpression,
BinaryExpression(SyntaxKind.AddExpression,
IdentifierName(UsernamePropertyName),
SyntaxHelpers.StringLiteral(":")),
IdentifierName(PasswordPropertyName))
))))
)),
ExpressionStatement(AssignmentExpression(SyntaxKind.SimpleAssignmentExpression,
MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression,
MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression,
IdentifierName(MessageParameterName),
IdentifierName("Headers")),
IdentifierName("Authorization")),
ObjectCreationExpression(WellKnownTypes.System.Net.Http.Headers.AuthenticationHeaderValue.Name)
.AddArgumentListArguments(
Argument(SyntaxHelpers.StringLiteral("Basic")),
Argument(IdentifierName(CacheFieldName))))),
ReturnStatement(LiteralExpression(SyntaxKind.DefaultLiteralExpression)));