function checkEnum(oEnum, sValue, sPropertyName) {
			var aValidValues = [];
			for (var sKey in oEnum) {
				if (oEnum.hasOwnProperty(sKey)) {
					if (oEnum[sKey] === sValue) {
						return sValue;
					}
					aValidValues.push(oEnum[sKey]);
				}
			}
			throw new TypeError("Unsupported Enumeration value for " + sPropertyName + ", valid values are: " + aValidValues.join(", "));
		}
Checks if a value exists within an enumerable list.

@name module:sap/base/config._.checkEnum
@function
@param {object} oEnum Enumeration object with values for validation
@param {string} sValue Value to check against enumerable list
@param {string} sPropertyName Name of the property which is checked
@returns {string} Value passed to the function for check
@throws {TypeError} If the value could not be found, an TypeError is thrown

@private