The document outlines the requirements for creating a UML class diagram for a graphical document editor that includes sheets and drawing objects, allowing for grouping of objects. Each group must consist of at least two members and cannot have overlapping memberships in other groups. Additionally, the document specifies ownership privileges for sharing with other users and restricts the creation of extra classes beyond those mentioned.

4. ASSIGNMENT 1
Prepare a UML diagram (class diagram) for a “graphical document
editor” that supports grouping. Assume that a document consist of
several sheets. Each sheet contains drawing objects, including texts,
geometrical objects and groups. A group is simply a set of drawing
objects; possibly including other groups. A group must contain at least
two drawing objects. A drawing object can be direct member of at most
one group. Geometrical objects include circles, ellipses, rectangles, lines
and squares. There is an owner of the each document; Owner has the
privilege to share the document with other users. [You are not allowed
to make extra classes except those described in above requirements.]
b. Briefly explain each relationship between classes.