history length = 2
Couldn't parse historical command 'echo ( a )': <Expected word type %s, got %s (Right_FuncDef, Word_Compound) None (word.CompoundWord parts:[(word_part.LiteralPart token:(token id:Lit_Chars val:a span_id:4))]) None>
.history length = 2
! echo -lhistory length = 2
! echo xxhistory length = 2
.! echo yyhistory length = 3
! echo "${five@P}"history length = 3
! echo $threehistory length = 3
.! echo -n $three ${4:-} "${five@P}"history length = 4
! echo ${two:-}history length = 4
! echo ${two:-}history length = 4
! echo 1history length = 4
! ls /echo/history length = 4
! echo ${two:-}history length = 4
history length = 4
history length = 4
! ls /echo/history length = 4
...
----------------------------------------------------------------------
Ran 6 tests in 0.005s

OK
! echo /echo/<frontend.reader.FileLineReader object at 0x7f9b7e96be90>
<frontend.reader.FileLineReader object at 0x7f9b7e96be50>
<frontend.reader.VirtualLineReader object at 0x7f9b7e96bf90>