验证如果函数导入是可组合的，则该函数导入必须具有返回类型。
命名空间： Microsoft.Data.Edm.Validation
程序集： Microsoft.Data.Edm（在 Microsoft.Data.Edm.dll 中）
语法
声明
Public Shared ReadOnly ComposableFunctionImportMustHaveReturnType As ValidationRule(Of IEdmFunctionImport)
用法
Dim value As ValidationRule(Of IEdmFunctionImport)
value = ValidationRules.ComposableFunctionImportMustHaveReturnType
public static readonly ValidationRule<IEdmFunctionImport> ComposableFunctionImportMustHaveReturnType
public:
static initonly ValidationRule<IEdmFunctionImport^>^ ComposableFunctionImportMustHaveReturnType
static val ComposableFunctionImportMustHaveReturnType: ValidationRule<IEdmFunctionImport>
public static final var ComposableFunctionImportMustHaveReturnType : ValidationRule<IEdmFunctionImport>