Imports of package btree

PathSynopsis
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
ioPackage io provides basic interfaces to I/O primitives.
sortPackage sort provides primitives for sorting slices and user-defined collections.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.
syncPackage sync provides basic synchronization primitives such as mutual exclusion locks.