Stellar Language Inclusion Checks

You can use Stellar language inclusion checks such as "in", "and", and "not" to define the content of the Stellar syntax.

in supports string contains. For example, 'foo' in 'foobar' == true
in supports collection contains. For example, 'foo' in [ 'foo', 'bar' ] == true
in supports map key contains. For example, 'foo' in { 'foo' : 5} == true
not in is the negation of the in expression. For example, 'grok' not in 'foobar' == true`