>>> from pyrsistent_extras import psequence
>>> seq1 = psequence([1, 2, 3])
>>> seq1
psequence([1, 2, 3])
>>> seq2 = seq1.append(4)
>>> seq2
psequence([1, 2, 3, 4])
>>> seq3 = seq1 + seq2
>>> seq3
psequence([1, 2, 3, 1, 2, 3, 4])
>>> seq1
psequence([1, 2, 3])
>>> seq3[3]
1
>>> seq3[2:5]
psequence([3, 1, 2])
>>> seq1.set(1, 99)
psequence([1, 99, 3])

>>> from pyrsistent_extras import pminheap
>>> heap1 = pminheap([(1,'a'), (2,'b')])
>>> heap1
pminheap([(1, 'a'), (2, 'b')])
>>> heap2 = heap1.push(3,'c')
>>> heap2
pminheap([(1, 'a'), (2, 'b'), (3, 'c')])
>>> heap3 = heap1 + heap2
>>> heap3
pminheap([(1, 'a'), (1, 'a'), (2, 'b'), (2, 'b'), (3, 'c')])
>>> key, value, heap4 = heap3.pop()
>>> (key, value)
(1, 'a')
>>> heap4
pminheap([(1, 'a'), (2, 'b'), (2, 'b'), (3, 'c')])