The friendship theme is developed through the relationship between the two friends that show the characteristics that a friendship should or should not have.
The theme is a message that is hidden in the text, for this reason, the reader must read the text and interpret it, to find the theme. In addition, the themes are developed from the behavior of the characters and the actions they promote.
You didn't show the excerpts your question refers to, which prevents me from showing you the development of the theme, but I hope the information above can help you.
More information on the theme is at the link:
https://brainly.com/question/4008478