You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: _frequency.rs
    path of file: ./repos/aws-sdk-rust/sdk/groundstation/src/types
    
    the code of the file until where you have to start completion: // Code generated by software.amazon.smithy.rust.codegen.smithy-rs. DO NOT EDIT.

/// <p>Object that describes the frequency.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct Frequency {
    /// <p>Frequency value. Valid values are between 2200 to 2300 MHz and 7750 to 8400 MHz for do
    
    pub fn build(self) -> ::std::result::Result<crate::types::Frequency, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::Frequency {
            value: self.value.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "value",
                    "value was not specified but it is required when building Frequency",
                )
            })?,
            units: self.units.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "units",
                    "units was not specified but it is required when building Frequency",
                )
            })?,
        })
    }