PY_OUT</code> result by executing
       <a class="xref" href="libpq-copy.html#LIBPQ-PQGETLINE"><code class="function">PQgetline</code></a> repeatedly, followed by
       <a class="xref" href="libpq-copy.html#LIBPQ-PQENDCOPY"><code class="function">PQendcopy</code></a> after the terminator line is seen.
       It should then return to the <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a> loop
       until <a class="xref" href="libpq-async.html#LIBPQ-PQGE