The using declaration lets you use a type in a package other than the package the type was defined in without having to specify the fully qualified name of the type.
UsingDeclaration
Insert a using declaration, after the optional package declaration and before any other declarations, that specifies the fully qualified name of the type. For example:
using com.myCorporation.custom.myCustomAggregate;
You can specify multiple using declarations in a file.
In a file, you cannot specify two using declarations that bring in types that have the same base name. See also Name Precedence.
You cannot specify a using declaration for named objects such as monitors, JMon monitors, and namespaces.