CountBuffers
status_t CountBuffers(int32* _count);
err = m_bufferGroup->CountBuffers(&curBufferCount);
if (fUsedBufferGroup->CountBuffers(&bufferCount) == B_OK) {
if (group->CountBuffers(&buffer_count) != B_OK)
int32 CountBuffers() const;
s = group->CountBuffers(&count);
s = group->CountBuffers(&count);
s = group2->CountBuffers(&count);
mBufferGroup->CountBuffers(&numBuffers);