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);
}

Start in the BuilderPatternFunctionsRewriter class and inspect how it handles method return types and return statements. Reproduce the shown static getter case, then verify that only methods returning this are rewritten and that the generated code has no type mismatch.

Written by the indexing model from the issue text.