# Couplers All the smells in this group contribute to excessive coupling between classes or show what happens if coupling is replaced by excessive delegation. ## Feature Envy A method accesses the data of another object more than its own data. This smell may occur after fields are moved to a data class. If this is the case, you may want to move the operations on data to this class as well. ### Treatment * Move Method * Extract Method ## Inappropriate Intimacy One class uses the internal fields and methods of another class. ## Message Chains In code you see a series of calls resembling `$a->b()->c()->d()`. ### Treatment * Hide Delegate * Extract Method ## Middle Man If a class performs only one action, delegating work to another class, why does it exist at all? ### Treatment If most of a method’s classes delegate to another class, Remove Middle Man is in order. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://xiaoyang-liu.gitbook.io/programming-notes/software-engineering/refactoring/code-smells/couplers.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.