Build an XML mission string that uses the RewardForCollectingItem mission handler.

def GetMissionXML(summary):
    ''' Build an XML mission string that uses the RewardForCollectingItem mission handler.'''
    
    positions = buildPositionList(items)
    
    return '''<?xml version="1.0" encoding="UTF-8" ?>
    <Mission xmlns="http://ProjectMalmo.microsoft.com" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <About>
            <Summary>''' + summary + '''</Summary>
        </About>

        <ServerSection>
            <ServerHandlers>
                <FlatWorldGenerator generatorString="3;7,220*1,5*3,2;3;,biome_1" />
                <DrawingDecorator>
                    <DrawCuboid x1="-50" y1="227" z1="-50" x2="50" y2="227" z2="50" type="air" />   <!-- to clear old items-->
                    <DrawCuboid x1="-50" y1="226" z1="-50" x2="50" y2="226" z2="50" type="monster_egg" variant="chiseled_brick" />
                    <DrawCuboid x1="-3" y1="226" z1="-3" x2="3" y2="226" z2="3" type="dirt" />
                    <DrawCuboid x1="-3" y1="227" z1="-3" x2="3" y2="227" z2="3" type="red_flower" variant="blue_orchid" /> <!-- yes, blue orchids are indeed a type of red flower. -->
                    ''' + getItemDrawing(positions) + '''
                </DrawingDecorator>
                <ServerQuitFromTimeUp timeLimitMs="150000"/>
                <ServerQuitWhenAnyAgentFinishes />
            </ServerHandlers>
        </ServerSection>

        <AgentSection mode="Survival">
            <Name>Delia</Name>
            <AgentStart>
                <Placement x="0.5" y="227.0" z="0.5"/>
                <Inventory>
                </Inventory>
            </AgentStart>
            <AgentHandlers>
                <RewardForCollectingItem>
                    <Item reward="10" type="planks" variant="spruce dark_oak" />
                    <Item reward="100" type="cooked_rabbit carrot baked_potato brown_mushroom"/>
                    <Item reward="500" type="bowl"/>
                    <Item reward="1000" type="rabbit_stew"/>
                </RewardForCollectingItem>
                <RewardForDiscardingItem>
                    <Item reward="-2" type="planks"/>
                    <Item reward="-6" type="cooked_rabbit carrot baked_potato brown_mushroom"/>
                </RewardForDiscardingItem>
                <ContinuousMovementCommands turnSpeedDegs="480"/>
                <SimpleCraftCommands/>
                <InventoryCommands/>
                <ObservationFromSubgoalPositionList>''' + getSubgoalPositions(positions) + '''
                </ObservationFromSubgoalPositionList>
                <ObservationFromFullInventory/>
                <AgentQuitFromCollectingItem>
                    <Item type="rabbit_stew" description="Supper's Up!!"/>
                </AgentQuitFromCollectingItem>''' + video_requirements + '''
            </AgentHandlers>
        </AgentSection>

    </Mission>'''