Copies data from the "from" Type into the "to" Type. Either Type may be
a Primitive, Composite, or Varies. If a Varies is provided, the operation is
performed on the result of calling its getData() method. A Primitive may be
copied into a Composite, in which case the value is copied into the first
component of the Composite. A Composite may be copied into a Primitive,
in which case the first component is copied. Given Composites with different
numbers of components, the first components are copied, up to the length
of the smaller one.
Copies contents from the source segment to the destination segment. This
method calls copy(Type, Type) on each repetition of each field (see additional
behavioural description there). An attempt is made to copy each repetition of
each field in the source segment, regardless of whether the corresponding
destination field is repeating or even exists.