Public method 'CorrectCase' on test class 'FileContentTests' should be marked as a Theory. Reduce the visibility of the method, or add a Theory attribute to the method. (https://xunit.net/xunit.analyzers/rules/xUnit1013)

Test data attribute should only be used on a Theory. Remove the test data, or add the Theory attribute to the test method. (https://xunit.net/xunit.analyzers/rules/xUnit1008)

Public method 'CorrectCase' on test class 'FileContentTests' should be marked as a Theory. Reduce the visibility of the method, or add a Theory attribute to the method. (https://xunit.net/xunit.analyzers/rules/xUnit1013)