d3js remove last tspan node

Question

I have something similar to this

var textBox = somecontainer.append('text')
...
textBox.append('tspan').text('First ')
textBox.append('tspan').text('Second ')
textBox.append('tspan').text('Third ')
...
textBox.append('tspan').text('nth ')

Later on I need to remove programatically the last child tspan node from the textBox stack. How ?