An S4 class to represent the header of .las or .laz files according to the
LAS file format specifications.
A LASheader
object contains a list
in the slot @PHB
with
the data read from the Public Header Block and list
in the slot @VLR
with
the data read from the Variable Length Records
PHB
list. Represents the Public Header Block
VLR
list. Represents the Variable Length Records