page object gem - when are the required methods generated?

I believe that when using page-object gem, having a method call like

link(:sym, text: "example.com")

generates three methods - sym, sym_element and sym? Can anybody clear the following doubts?

1. When exactly are these methods created i.e., when does the page-object class uses define_method to implement these methods?

2. These method calls (link(:sym, text: "example.com") are present directly inside the class without being wrapped inside another method!! Is it allowed to have statements directly inside a class without being wrapped in a method? If so, what is the use of those statements?

   class Test
     include PageObject
   
     def example_method        
       puts "example method"    
     end
   
     link(:sym, text: "example.com")        
   end
   

3. Can I call (link(:sym, text: "example.com") inside a method present in my class. Doing it this way throws a NoMethodError!! Is this not allowed?

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Link to original article：https://stackoverflow.com/questions/19908085/page-object-gem-when-are-the-required-methods-generated