The BuilderPatternFunctionsRewriter class has some incorrect handling methods.

orgin code is:
` private static ClassA staicField;

public static ClassA GetStaicField()
{
return staicField;
}`

will be written to
` private static ClassA staicField;

public static ClassA_Patched_0 GetStaicField()
{
return staicField;
}`

The above code may lead to type mismatch errors.

Only "return this" needs to be rewrite. Perhaps it is necessary to add a check for whether there is a "return this".

static bool ReturnsThis(MethodDeclarationSyntax method)
{
var returnStatements = method.DescendantNodes().OfType();

return returnStatements.All(r => r.Expression is ThisExpressionSyntax);
}