src <- list(a=list(a.1=list(a.1.1=list(a.1.1.1=1, a.1.1.1=2, a.1.1.1=3), 
    a.1.2=1, a.1.2=2, a.1.2=3), a.2=list(a.2.1=list())), b=NULL, 
    c=data.frame(a=1:3, b=3:5))

listDuplicatesProcess(
    src=src,
    handle.duplicates="stop",
    do.return.flat=TRUE,
    .delim.index="-",
    .delim.path="/"
)

#+++++

listDuplicatesProcess(
    src=src,
    handle.duplicates="keep.original",
    do.return.flat=TRUE,
    .delim.index="-",
    .delim.path="/"
)
listDuplicatesProcess(
    src=src,
    handle.duplicates="keep.original",
    do.return.flat=FALSE,
    .delim.index="-",
    .delim.path="/"
)

#+++++

listDuplicatesProcess(
    src=src,
    handle.duplicates="keep.first",
    do.return.flat=FALSE,
    .delim.index="-",
    .delim.path="/"
)

#+++++

listDuplicatesProcess(
    src=src,
    handle.duplicates="keep.last",
    do.return.flat=FALSE,
    .delim.index="-",
    .delim.path="/"
)

#+++++

listDuplicatesProcess(
    src=src,
    handle.duplicates="index.duplicates",
    do.return.flat=FALSE,
    .delim.index="-",
    .delim.path="/"
)
listDuplicatesProcess(
    src=src,
    handle.duplicates="index.all",
    do.return.flat=FALSE,
    .delim.index="-",
    .delim.path="/"
)

#+++++

src.flat <- flatten(src, do.index=TRUE)

listDuplicatesProcess(
    src=src.flat,
    handle.duplicates="keep.original",
    do.return.flat=FALSE,
    .delim.index="-",
    .delim.path="/"
)

#+++++

testData = expand.grid(letters[1:4],c(1:3))
testData$keep=F
uniqueIDS = unique(testData$Var1)
for(thisID in uniqueIDS) {
    firstCaseOnly = match(thisID,testData$Var1)
    testData[firstCaseOnly,"keep"]=T
}

(testData = testData[testData$keep==T,])