Sets up a TRY block.
A TRY block identifies a block of code that might throw exceptions. Those exceptions are handled in the following CATCH and AND_CATCH blocks. Recursion is allowed: exceptions may be passed to an outer TRY block, either by ignoring them or by using the THROW_LAST macro. End the TRY block with an END_CATCH or END_CATCH_ALL macro.
For more information, see the article Exceptions.
See the example for CATCH.