code: function (oInterface, oPathValue, iIndex, sEdmType) {
  			var oParameter = Basics.descend(oPathValue, iIndex),
  				oResult;
  
  			oParameter.asExpression = true;
  			oResult = Expression.expression(oInterface, oParameter);
  
  			if (sEdmType && sEdmType !== oResult.type) {
  				Basics.error(oParameter,
  					"Expected " + sEdmType + " but instead saw " + oResult.type);
  			}
  			return oResult;
  		}
docs: Evaluates a parameter and ensures that the result is of the given EDM type.
  
  The function calls <code>expression</code> with <code>bExpression=true</code>. This will
  cause any embedded <code>odata.concat</code> to generate an expression binding. This
  should be correct in any case because only a standalone <code>concat</code> may generate
  a composite binding.
  
  @param {sap.ui.core.util.XMLPreprocessor.IContext|sap.ui.model.Context} oInterface
  the callback interface related to the current formatter call
  @param {object} oPathValue
  path and value information pointing to the parameter array (see Expression object)
  @param {number} iIndex
  the parameter index
  @param {string} [sEdmType]
  the expected EDM type or <code>undefined</code> if any type is allowed
  @returns {object}
  the result object