A configurable parameter that replaces one or more fields in the
template. Parameterizable fields: - Labels - File uris - Job
properties - Job arguments - Script variables - Main class (in
HadoopJob and SparkJob) - Zone (in ClusterSelector)
.. attribute:: name
Required. Parameter name. The parameter name is used as the
key, and paired with the parameter value, which are passed to
the template when the template is instantiated. The name must
contain only capital letters (A-Z), numbers (0-9), and
underscores (_), and must not start with a number. The maximum
length is 40 characters.
Optional. Brief description of the parameter. Must not exceed
1024 characters.
