The Complete Solidity Course - Zero to Advanced for Blockchain and Smart Contracts - Solution - Modifier Function

The video tutorial guides viewers through creating and implementing a 'modifier' in code, specifically focusing on the 'only by' modifier. It explains how to set up the modifier to restrict access based on the message sender's address, ensuring only authorized users can execute certain functions. The tutorial includes testing the modifier with different accounts, handling errors, and understanding why certain errors occur. The video concludes with a brief introduction to the next topic, 'only after', encouraging viewers to take a break before continuing.

How does the text suggest testing the functionality of the modifier?

Describe the process of changing the owner using the modifier.