sequenceDiagram
    actor User

    rect rgb(204, 255, 255)
    note right of User: Create a board
    create participant Board
    User--)Board: Board(int width, int height)
    create participant CollectionElements
    Board--)CollectionElements: HashMap<>();
    create participant Coordinate
    Board--)Coordinate: Coordinate(int minX, int minY)
    Board--)Coordinate: Coordinate(int maxX, int maxY)
    end

    rect rgb(229, 255, 204)
    note right of User: Create and add an element
    create participant Element
    User--)Element: Element() implement ElementInterface
    User->>Board: addElement(Element element, int x, int y)
    Board--)Coordinate: Coordinate(int x, int y)
    Board-)Coordinate: testCoordinate(Coordinate(int x, int y)
    alt coordinate are invalid
        Coordinate--)Board: IndexOutOfBoundsException()
        Board--)User: IndexOutOfBoundsException()
    else coordinate are valid
        Board->>CollectionElements: put(Element element, Coordinate coordinate)
    end
    end

    rect rgb(255, 204, 204)
    note right of User: Get elements of a coordinate
    User-)Board: getElements(int x, int y)
    Board-)Coordinate: testCoordinate(Coordinate(int x, int y)
    alt coordinate are invalid
        Coordinate--)Board: IndexOutOfBoundsException()
        Board->>User: IndexOutOfBoundsException()
    else coordinate are valid
        Board-)CollectionElements: Get elements at given coordinate
        CollectionElements--)Board: return elements
        Board->>User: return elements
    end
    end

    rect rgb(255, 204, 255)
    note right of User: Remove an element
    User-)Board: removeElement(Element element)
    Board-)CollectionElements: containsKey(Element element)
    alt element not in CollectionElements
        CollectionElements--)Board: return false
        Board--)User: return false
    else element in CollectionElements
        CollectionElements--)Board: return true
        Board-)CollectionElements: remove(Element element)
        Board--)User: return true
    end
    end

    rect rgb(204, 204, 255)
    note right of User: Clear coordinate
    User-)Board: clearCoordinate(int x, int y)
    Board->>Board: getElements(int x, int y)
    note over Board: see Get elements of a coordinate
    Board->>Board: removeElement(Element element)
    note over Board: For each element found, see Remove an element
    end